Ores and Minerals PDF

 Ore bodies are unevenly distributed throughout the Earth’s crust. This is the main reason why a country will never be self – enough in terms of natural resources and supplies. Potential ore bodies are located by recognizing that a geologic process or combination of processes can produ...

 Ore bodies are unevenly distributed throughout the Earth’s crust. This is the main reason why a country will never be self – enough in terms of natural resources and supplies. Potential ore bodies are located by recognizing that a geologic process or combination of processes can produce a localized enrichment of one or more minerals and that these processes only happen in particular types of environment.  Hydrothermal Fluid Circulation – the most common type of ore mineral deposition process. Metamorphic Processes – the alteration and recrystallization of minerals and aids the formation and localization of economically – important minerals. Magmatic Processes – create ore minerals which are concentrated due to their premature recrystallization or separation from magma.  Kimberlite Magma – originates deep within the mantle and is the source of diamonds, which only crystallize at depths greater than 150km. Chemical Sedimentary Process – form evaporate deposits from the precipitation of salt water minerals. Action of Currents – flowing surface water tends to take sediments along. If the wave action and strength is constant, it causes a selective sifting effect that removes the sediments and leaves behind those that are heavier in placer deposits.  Chemical Weathering – all rocks are exposed to oxygen and water, that is, chemical changes in their mineral components that result in their alteration into other minerals and into the formation of residual ore deposits.  Mining – a set of processes in which useful resources are withdrawn from a stock of any nonrenewable resource. Mining ores is an intensive and sophisticated process that varies depending on the mineral and on whether they are excavated, stripped or brought via tunnels and shafts.  Looking for the ore body, a deposit that can yield a large amount of the required ore mineral. Prospecting or Exploration  Extracting a part of the ore to determine the resulting ore, its quality and the amount of the ore mineral (grade). Drilling  Determines the ore’s size, shape and grade distribution throughout the deposit to apply appropriate mining methods. Modelling  Considering on the social and environmental aspects and finding ways of mitigating any consequence of the mining operation, with the purpose of bringing the area back as close to its original state as Identifying and Assessing the possible. Potential Impacts  Creating the appropriate mine and operational design and proceeding with the construction once all the necessary permits Designing and Constructing are acquired. the Mine  Separation of high – grade ores from the rest of the deposit. Ore Extraction  Crushing and concentration of ores, waste materials are released. Milling  Closure of the depleted mine. The mine site is cleaned up and reclaimed or rehabilitated for other purposes. Mine Site Decommissioning  The minerals are contained in ores. After processing, only the mineral is used, and the remaining of the ore is disposed as waste. These wastes, if not handled and managed properly, can cause serious environmental problems. Mining generates a lot of wastes. For example, a mine obtains one kilo of copper. In the process of extracting one kilo, 99 kilos of wastes are removed. Simply put, ore will be one percent (1%) useful mineral and 99% wastes.  Energy Source Energy Production Usage Environmental Impact Oil, Petroleum Non Renewable 38% of world’s Refining and consumption in 2000 consuming produce air, Easily transported water and solid waste pollutants. Large portion in transportation industry Natural Gas Non Renewable 20% of world’s Produces fewer consumption in 2000 pollutants than oil and Flexible for use in coal and less CO2 industries, transportation, power generation  Energy Source Energy Production Usage Environmental Impact Coal Non Renewable Primary resource for Produces CO2 and electricity other air, water and solid pollutants Biomass: Wood and Renewable Low energy potential Burning emits CO2 organic waste relative to other and other pollutants including societal resources In terms of timber, it is Possible toxic waste easily harvested and byproducts from abundant in certain societal waste areas; But it takes a Loss of habitat when long time to grow a trees are harvested, tree unless sustainable tree farms  Energy Source Energy Production Usage Environmental Impact Hydro – electric Renewable Low economic cost Destruction of though high start farmlands, Clean resource up cost dislocation of with high people, loss of efficiency habitat, alteration Influenced by of stream flows climate and geography  Energy Source Energy Production Usage Environmental Impact Solar Power Renewable Technology is already Large land use (Photo – Voltaic) in use for remote applications and non- centralized uses where it is economically competitive with alternatives High economic cost particularly in terms of start Unlimited resource set up that is clean, efficient, safe and renewable Dependent on climate and geographical location Need a storage system for the energy to ensure reliability Not advanced enough for global use  Heavy metal wastes can seep through soil making it poisonous for plants to grow. Water sources can be contaminated by the acid used in the mining process. Tailings, a by-product of milling ores, can travel from the dump ponds into the water source of nearby communities. In the Philippines, some of these wastes damaged mangroves, reefs, and impaired agriculture.  It is then crucial that waste products be controlled to prevent them from making a more pronounced impact in our environment. There are ways to lessen the wastes and effects on the environment. 1. Recent improvements in technology enable mining companies to extract more minerals from the ores with fewer wastes in production. 2. The mining companies must be able to plan out their sites from exploration to rehabilitation. 3. The mining company must also ensure that they are able to restore the community that was displaced because of their activities. 4. Tailings from mines can be zoned in and surrounded by lands so that plants can avoid erosion of the ponds thus minimizing the possibility of seepage of the tailings. 5. Mine structures should be designed at par or even surpassing current rules and regulations set by the government and international standards. 6. Other mining practices include reforestation, slope stabilization, maintenance for dump facilities, managing and monitoring air and water quality, erosion control, and water conservation.  Philippine Mining Act of 1995 or RA 7942 – this law aims primarily to establish rules and regulations of mining practices in the country and to attract foreign investors to explore the potential of minerals in the country. At the same time, the law also intends to balance the mining industry, the culture, and the protection of the environment.  Executive Order (EO) 79, Series of 2012 – aimed to strengthen the provisions of the Philippine Mining Act of 1995. This EO imposed stricter rules on the environmental protection and waste management of different mining companies. 1. Job Creation. Mining process results in the creation of job opportunities to the local people and attracts other professionals in the market. 2. Boost Business Activities. Mining results in the rise of business activities and the rise of per capita income. This results in a higher human development index due to increased life expectancy and per capita income. 3. Enormous Earning. Mining for exportation purposes results in high enormous earnings to people working in the mines and boost the financial sector. 4. Extract Essential Sources of Energy. Mining results in the extraction of raw materials like oil, coal, gas, iron ores, and minerals providing efficient use of energy. 5. Development of Social Amenities. Mining in an area facilitates the development of social services like schools, healthcare, water for the employees working in the area and their families. 6. Development of Infrastructure. It leads to the development of the means of transport and communication in the area. The extracted raw materials need to be transported for further processing leading to improved means of transport. 7. Steer Technological Development. Advanced mining tools are used to safely create underground subway tunnels and pipes. Earth-moving technologies and environmental control systems are also needed to manage water flow, temperature, and airflow in mining areas. 8. Provides Essential Resources. Mining provides us with essential goods and services for use in our everyday life like the cookware and electronic components. 9. Spur Economic Growth. Selling of gold, coal, other mined materials, and job opportunities boost the economic growth of the country. It leads to the generation of income to the local government which directly contributes to the economic growth. 10. Environmental Stewardship. Advanced technological tools are being used in the mining sector to safeguard environmental impacts. It also promotes environmental awareness through rehabilitation programs in the mining areas. 1. Water Pollution. Mining results in contamination of the soil and groundwater from the chemicals in the mining zones. Contaminated groundwater can flow to rivers or lakes contributing to water pollution. 2. Leads to Deforestation. Mining in a certain area leads to deforestation as trees are cleared to pave way for the mining activity. The clearing of trees or forests contributes to climate change. 3. Cause Landslides. Improper and illegal mining in an area can result in some natural calamities like landslides and floods which can cause death to animals and people. 4. Affects Aquatic Life. Contaminated water from mining zones affects aquatic organisms (both micro and macro organism). It also affects the growth and health of terrestrial organisms like animals and vegetation. 5. Acid Rock Drainage. Sub-surface mining require water to be pumped out of the mine to avoid any flooding. If the water is not pumped out, it results in the creation of acid rock drainage issue. 6. Destruction of the Ecosystem. Clearance of the mining area and destruction of large portions of the forests lead to soil erosion in the area. 7. Loss of Biodiversity. Any illegal mining can affect the current biodiversity of the area. It affects animal and plant species in a particular habitat. 8. Danger to People. The mine are very dangerous and they weaken the structure above or around the area. Mine shaft can collapse causing death to people underground. 9. Harmful to Human Health. The miners can suffer from some skin diseases, lungs, and respiratory problems which are caused by the chemicals released in the air and water from the mining zones. 10. Heavy Metal Contamination. Water from the mines may contain metals like lead, cadmium, and other heavy metals which can contaminate the groundwater.  "What's the matter is that you keep holding me like this delicate flower that's going to break every time you look at me. That is what is the matter.“ -Dr. April Kepner Ores and Minerals John Aldrich G. Cortez, RN  Minerals are resources that must be sustained for present and future generations. Ore Minerals: How They Are Found and Mined A mineral is a naturally occurring, homogeneous inorganic substance that has a definite chemical composition. In this case, some important elements including metals can be economically extracted from specialized rocks called ore deposits. Methods of Mining Surface mining is used to extract ore minerals near the surface of the earth. The soil and rocks that covered the ores are removed through blasting. Blasting is a controlled use of explosives and gas exposure to break rocks. Some examples of surface mining are open-pit mining, quarrying, and strip mining. Methods of Mining Underground mining is used to extract the rocks, minerals, and other precious stones that can be found beneath the earth’s surface. In underground mining, miners need to create a tunnel so they can reach the ore minerals. This kind of mining is more expensive and dangerous as compared to surface mining because miners need to use explosive devices to remove the minerals from the rocks that cover them. Mineral Processing Mineral processing is the process of extracting minerals from the ores, refining them, and preparing these minerals for use. The primary steps involved in processing minerals include sampling and analysis, comminution, concentration, and dewatering. Mineral Processing Sampling is the removal of a portion which represents a whole needed for the analysis of this material. One or more samples are needed. Mineral Processing Analysis is important to evaluate the valuable components in an ore. This includes chemical, mineralogical, and particle size analysis. a. Chemical analysis uses electric discharge which excites the elements in the sample to emit a certain spectra which will reveal the identity of the elements as well as its concentration. Mineral Processing b. Mineralogical analysis uses heavy liquid-testing that aims to separate the less dense, same density, and denser materials. Coarsely grounded minerals are classified according to particle size through sieving. Mineral Processing c. Comminution is the process where the valuable components of the ore are separated through crushing and grinding. This process begins by crushing the ores to a particular size and finishes it by grinding the ores into a powder form. Mineral Processing d. Concentration involves the separation of the valuable minerals from the raw materials. Optical separation - a process used in the concentration of minerals with distinct contrasting colors (black and white) seen with the naked eye. Mineral Processing Gravity separation - process that uses the density of minerals as the concentrating agent and performs a sink and float separation of water and the grounded minerals. Flotation separation - the most widely used method that makes use of the mineral’s wettability to water or chemicals. Mineral Processing Magnetic separation - a process that involves different degrees of attraction of minerals to magnets. Electrostatic separation - a process that separate the mineral particles based on their electric charges. Mineral Processing e. Dewatering uses the concentrates to convert it to usable minerals. This involves filtration and sedimentation of the suspension, and drying of the solid material harvested from this suspension.  "Your words will disappear. Your house will disappear. Your name will disappear. All memory of you will disappear.“ -Sansa Stark Important Minerals in Society John Aldrich G. Cortez, RN Home and Personal Use Aside from salt, other minerals compose some of the items and equipment found in our houses. Feldspar is a component for ceramics, glassware, and pottery. It is also an ingredient in making soaps. Fluorite is also used in ceramics and pottery. It is commonly known as a component of toothpaste in the form of fluoride. Home and Personal Use Gold, silver, and platinum are made into pieces of jewelry and other important articles at home. Quartz is used for the production of glass and fiberglass usually used at home. Electronics, Infrastructure, and Manufacturing Numerous minerals are important to infrastructure and manufacturing. A very good example of this is copper. Copper serves as an important material in electronics and wiring because of its conductive properties. Silver is utilized in electronics for the same reason. Electronics, Infrastructure, and Manufacturing Silica is a mineral that contains silicon, a metalloid that has some properties of metals such as the ability to conduct electricity. Tungsten and molybdenum are used widely for the filament in incandescent bulbs because of their high melting points. Iron ores are used for stainless steel production. Electronics, Infrastructure, and Manufacturing Barium, chromite, cobalt, copper, molybdenum, and nickel serve as alloys in the production of other metals. Bauxite is an ore where aluminum is derived. It is important for the production of cement for construction. Copper and lead are also utilized widely in the construction field. Electronics, Infrastructure, and Manufacturing Quartz, in the form of sand, is also valuable in construction and manufacturing. Graphite, known in your pencil "lead”, can also be used in manufacturing. Economics Mining of minerals contribute to the gross domestic product (GDP) of a country. Gold is used as a reserve and serves as a backup for currencies. The amount of reserves of gold correlates to inflation. If the central bank of a country buys gold, the country’s currency is affected because of the fluctuations in the supply and demand of the currency. Precious Minerals and Other Uses Some minerals are used as gemstones. Rubies and sapphires contain aluminum oxide. Emeralds are from the mineral beryl. Diamond, a form of carbon, is considered as the most precious mineral. It is also the hardest mineral (10 on the Mohs Scale). Though commonly used for jewelry, some uncut diamonds are placed as additive for metal cutters because of its hardness. Precious Minerals and Other Uses Quartz is also considered as a semi- precious mineral. In some cases, minerals are used in the medical field. Examples of these minerals are barium that is a helpful additive to medicine in x-rays of the digestive system, and iron which is used to treat anemia.  “Sometimes when I'm trying to understand a person's motives, I play a little game. I assume the worst.“ -Sansa Stark John Aldrich G. Rocks and Cortez, RN Minerals  The diversity of minerals on Earth are based on the similarities and differences of their chemistry.  Resources such as rocks and minerals are of great value to people. They provide materials and products that the present society demands. They are used as oscillators in electronic devices, provide taste to food or ingredients for plaster boards. Characteristics of Minerals Naturally – occurring – minerals exist naturally. Steel and synthetic diamonds are created artificially, therefore are not minerals. Inorganic – minerals are limited to substances formed through inorganic processes and exclude materials derived from living which involved organic processes. Characteristics of Minerals Solid – all liquid and gases, and even those that are naturally formed are not considered minerals. Definite Chemical Composition – the chemical composition of minerals should express the exact chemical formula with the elements and compounds in specific ratio. Characteristics of Minerals Ordered Internal Structure – the atoms in minerals are organized in a regular, repetitive geometric patterns or crystal structure. Composition of Minerals Silicates – silicon – oxygen tetrahedrons. Oxides – metal cations bonded to oxygen anions. Sulfides – metal cation bonded to sulfide. Sulfates – they usually precipitate out of water near Earth’s surface. Composition of Minerals Halides – composed of halogen ion. Carbonates – characterized by the presence of carbonic ion. Native Metals – composed of single metal. Rocks Petrology – the branch of geology that studies rocks, and the conditions in which rocks form. Rocks – natural solid materials that make up the most of the Earth’s lithosphere. Rocks Rocks are classified according to how they are formed. Rock Cycle – a model that describes the formation, breakdown, and reformation of a rock as a result of sedimentary, igneous, and metamorphic processes. Rocks Process Product Melting Magma Crystallization Igneous Rock Uplift and Exposure Weathering and Erosion Sediments Transportation Deposition Sedimentary Rock Lithification Metamorphism Metamorphic Rock Rocks Rocks Geologically, rocks can be classified into three. 1. Igneous Rocks 2. Sedimentary Rocks 3. Metamorphic Rocks Igneous Rock Igneous Rock – formed by the cooling or solidification of magma or lava. Latin, Ignis – Fire. This make sense because these rocks are formed by volcanic activity. Igneous Rock Magma – a molten rock generated by partial melting of rocks in Earth’s mantle. Magma consists mainly of silicon and oxygen, lesser amounts of aluminum, calcium, sodium, potassium, magnesium and iron. Formation of Igneous Rock Igneous rocks are formed from the cooling and solidification of magma or lava. Formation of Igneous Rock 1. Below the Surface, from Granite slow cooling magma – Diorite formation of crystals Syenite that are visible to the naked eye. These types of igneous rocks cool underneath the surface as plutons. Formation of Igneous Rock 2. On the surface, from Basalt rapidly cooling magma – Andesite very small crystals that Rhyolite may not be visible without the use of a magnifying lens. Igneous rocks like these are extruded during volcanic eruptions. Formation of Igneous Rock 3. On the surface, from Ignimbrite the consolidation of Tuff particle erupted by Volcanic explosive volcanic Breccia activity – a hybrid of igneous and sedimentary processes. Igneous Rock Types of Igneous Rock a. Extrusive Igneous Rock – Volcanic rock. Molten rocks solidify at the surface (lava). They are cooled lava, which are molten rocks ejected on the surface through volcanic eruptions. They are fine-grained due to abrupt cooling on the surface. Igneous Rock Types of Igneous Rock b. Intrusive Igneous Rock – Plutonic rock. Igneous rocks formed underneath the earth. They are coarse-grained due to the slow cooling of magma allowing crystal growth. Igneous Rock Igneous Rock Igneous Rock Igneous rocks can also be classified based on grain size, general composition, and percentage mineral composition. Igneous Rock Sedimentary Rock Sedimentary Rock - Rock that are formed by the deposition and subsequent cementation of that material at the Earth's surface and within bodies of water. Lithification – the process by which the sediments are transformed into solid sedimentary rock. Sedimentary Rock Types of Sedimentary Rock a. Clastic Sedimentary Rock - made by compaction and cementation of fragments and are identified by size of fragments. Compaction – as piles of sediments accumulate, the underlying materials are compacted by the weight of the overlying layers. Formation of Sedimentary Rock 1. From the concentration of Shale sediments that have been Sandstone deposited, buried and Conglomerate compacted for a long period of time – Clastic, differentiated based on size of sediments. Formation of Sedimentary Rock 2. From the precipitation of Limestone minerals from ions in Dolostone solution – rocks that are Rock Salt exposed to water and oxygen can undergo chemical changes that breaks down their chemical components. Formation of Sedimentary Rock 3. From the compaction and cementation of plant or animal remains – Bioclast. Coquina Organic Limestone Sedimentary Rock Types of Sedimentary Rock Cementation – Sediments are converted into sedimentary rock. b. Non Clastic Sedimentary Rock - form from chemical reactions, chiefly in the ocean. Sedimentary Rock Sedimentary Rock Metamorphic Rock Metamorphic Rock - Rocks which are formed by heat and pressure changing one type of rock into another type of rock. These rocks came from preexisting rocks, parent rocks that undergo changes. Metamorphic Rock Metamorphism – the change of minerals or geologic texture in pre-existing rocks, without the protolith melting into liquid magma. The change occurs primarily due to heat, pressure, and the introduction of chemically active fluids. Formation of Metamorphic Rock 1. Dominant altering factor Slate is pressure – the flat Schist elongated mineral Gneiss components of pre- existing rock react by aligning perpendicular to the axis of pressure. Formation of Metamorphic Rock 2. Dominant altering factor Marble is heat – direct contact Quartzite between an older rock material and an intruding body of magma. Metamorphic Rock Types of Metamorphic Rock a. Foliated Metamorphic Rock – have layered or banded appearance produced by exposure to high temperatures and pressures. b. Non – Foliated Metamorphic Rock – with blocky shapes and do not have banding. Metamorphic Rock  “Change. We don't like it. We fear it, but we can't stop it from coming. We either adapt to change or we get left behind. It hurts to grow, anybody who tells you it doesn't is lying, but here's the truth sometimes the more things change the more they stay the same. And sometimes, change is good. Sometimes change is everything.” -Dr. Meredith Grey Rocks and Minerals JohnAldrichG. Cortez,RN Rocks and Minerals Earth’s materials include rocks and minerals. They exhibit characteristics features and have economic value. Earth’s rock undergo transformation. Rocks and Minerals Mineral – a naturally occurring, inorganic, solid material that has a fixed structure and a definite chemical composition. Mineralogy – the study of minerals and their properties. Rocks and Minerals There are several laboratory and field techniques used to distinguish minerals based on physical and chemical properties. Some minerals can be identified with the use of high-powered instruments while some can be assessed through their physical properties. Rocks and Minerals Rocks – consist of aggregates of minerals. Minerals – the building blocks of rocks. They are made up of one or a number of chemical elements with a definite / orderly chemical composition and crystal structure. Physical Properties of Minerals 1. Color Depends on the elements which constitute the crystal lattice – the arrangement of atoms, or groups of atoms, in a specific pattern and with high symmetry. The reflection of certain wavelengths of light by the crystal lattice results in the color perceived by the observer. Physical Properties of Minerals 2. Streak the color of the mineral in its powdered form. Physical Properties of Minerals Mineral gems come in different colors and streak. Physical Properties of Minerals 3. Luster The relative differences in the opacity and transparency of a mineral as light is reflected on its surface. This describes the 'sparkles' of the mineral surfaces. Physical Properties of Minerals Minerals maybe opaque, translucent or transparent. Physical Properties of Minerals 4. Specific Gravity The ratio of the weight of the mineral to the weight of the water with an equal volume. It can be determined by using a balance. Physical Properties of Minerals Mineral Specific Gravity Copper 8.9 Silver 10.5 Lead 11.3 Gold 19 Physical Properties of Minerals 5. Hardness The measure of the resistance of a surface to abrasions or scratches. Dependent on the chemical composition and the crystalline structure of a mineral. Physical Properties of Minerals Physical Properties of Minerals Scale Description Field Hardness 1 Can be rubbed off on a finger 2 Can be scratched with a fingernail Guide 3 Can be scratched with a coin 4 Can be scratched with difficulty with a knife 5 Can be scratched with a knife blade 6 Can be scratched with a piece of glass 7 Can be scratched with a piece of quartz 8 – 10 Mineral is too hard to be included in this scale Physical Properties of Minerals 6. Cleavage The tendency of the mineral to be split or broken along flat surfaces. It is described how a mineral breaks along weakness plain. The quantity of cleavage can be described in how clearly or easily the mineral breaks like perfect, good, distinct, poor or indistinct. Physical Properties of Minerals 6. Fracture the texture or shape of the mineral’s surface when the mineral breaks into forms other than flat surfaces. 7. Tenacity refers to the behavior of the mineral under deformation or stress such as cutting, crushing, bending, or hitting. Physical Properties of Minerals 8. Crystal Habit The growth crystal pattern of a mineral as single or aggregated. Over all shape of a mineral. Common shapes include needlelike (acicular), plantlike (dendritic), kidney – shaped (reniform), elongated in one direction (prismatic) and broad and flat (tabular). Physical Properties of Minerals Chemical Properties of Minerals 1. Solubility The ability of a substance to dissolve in a solvent at a specified temperature. For example, biotite, a mineral commonly found in igneous rocks, is soluble in both acid and base solutions. The dissolution releases the loosely-bound potassium ions in the mineral. Chemical Properties of Minerals 2. Melting Point The temperature at which solid turns into liquid. Minerals composed of atoms that are tightly bonded within the crystal structure have high melting points. For example, quartz melts above 1670°C. Common Rock – Forming Minerals 1. Quartz A chemical composition of SiO2. It is a glassy-looking hard substance with white streaks. Despite its hardness, with a Mohs hardness of 7, it is quite brittle. Common Rock – Forming Minerals Pure quartz is clear and transparent. Colored varieties of quartz are due to elemental impurities built into its lattice. The grains of quartz, in general, are irregular in shape. Common Rock – Forming Minerals 2. Feldspar Has a chemical composition of XAl(1−2)Si(3−2)O8, where X is K, Ca, or Na. It is quite hard with a Mohs hardness of 6. Common Rock – Forming Minerals It is a light-colored material, usually white, but they can have lighter shades of red or green. It has a glassy luster. In rocks, feldspar forms rectangular crystals that break along flat faces. Common Rock – Forming Minerals 3. Mica Any group of hydrous potassium aluminum silicate minerals. The most common examples are clear muscovite and black biotite. Mica is soft, with Mohs hardness ranging from 2 to 2.5. Common Rock – Forming Minerals It is easily identified by its perfect cleavage, reducing it to thin smooth flakes. Its shine is responsible for the flashes of light in rocks such as granite and slate. Common Rock – Forming Minerals 4. Pyroxene Have a general composition of XY(Al,Si)2O6 where X is Ca or Mg and Y is either Mg,Fe,Al. Augite is the most common of this group. It has a glassy luster with streaks of white, light green, or light brown. Common Rock – Forming Minerals It is generally black in color and has stubby prismatic crystals. Its key feature is its two cleavages at around 90°. Common Rock – Forming Minerals 5. Amphibole Has a dark color with a Mohs hardness ranging from 5 to 6. Hornblende is the most common amphibole. Common Rock – Forming Minerals It has a glassy luster and an opaque characteristic. Its crystals are very long and very thin. Common Rock – Forming Minerals 6. Olivine A silicate mineral with a general chemical composition of (Mg,Fe)2 SiO4, but calcium, manganese, and nickel can be substituted for magnesium and iron. It is known for its distinct olive-green color and commonly used in the gemstone industry as peridot. Common Rock – Forming Minerals It is a glassy looking and transparent substance that is almost as hard as quartz. Its crystals have a granular shape.  “I believe that even though you made this mistake, you will be okay. I believe we survive. I believe that believing we survive is what makes us survive.” -Dr. Izzie Stevens