Lesson 1 & 2 Elementary Knowledge on Symmetry of Crystallographic Systems PDF

Lesson 1: Elementary Knowledge on Common Accessory Minerals Symmetry of Crystallographic Systems o zircon OLIVINE o monazite o apat...

Lesson 1: Elementary Knowledge on Common Accessory Minerals Symmetry of Crystallographic Systems o zircon OLIVINE o monazite o apatite,  crystallizes first crystallizes first, at o titanite between 1200° and 1300°C., at between o tourmaline 1200° and 1300°C. o pyrite NORMAN LEVI BOWEN o opaques.  born in Kingston Ontario, studied 8 Elements Make up 98% of the Earth’s Crust geology at Queen’s University and then o oxygen at MIT in Boston o silicon  carried out groundbreaking experimental o aluminium research into the processes of cooling o iron magmas o magnesium  one of the results of his works is The o calcium Bowen reaction series o sodium Lesson 2: Physical Properties of Minerals o potassium ROCKS Physical Properties of Minerals  composed of minerals COLOUR MINERAL  It is one of the most obvious characteristics of a mineral, but  is a naturally occurring substance which generally not the most useful diagnostic is usually solid, crystalline, stable at feature. room temperature and inorganic. CRYSTAL HABIT There are almost 5000 known mineral species, yet the vast majority of rocks are formed from  refers to the characteristic shape of a combinations of a few common minerals, mineral unit referred to as “rock-forming minerals”  euhedral - Crystals with well-developed faces (for example, garnet crystals are Rock-forming Minerals often euhedral) o feldspars  may also occur as aggregates of o quartz crystals o amphiboles Acicular – needle-like o micas o olivine Granular – aggregates of crystal o garnet Bladed – blade-like, slender and flattened o calcite o pyroxenes Hexagonal -six-sided ACCESSORY MINERALS Botryoidal – grape-like masses  Minerals occurring within a rock in small Massive – no distinct shape quantities Columnar – long, slender prisms Octahedral – eight-sided Cubic – cube-shaped Greasy – the appearance of being coated with an oily substance; may also be greasy to the Platy – flat, tablet shape touch Dendritic – tree-like, branching in multiple Pearly – the whitish iridescence of materials directions such as pearls Prismatic – elongate, prism like Vitreous – like glass Fibrous – very slender prisms Silky – like silk fabric Radial or Stellate – radiating outwards from a Resinous – like a resin central point, star-like Metallic – metal-like in appearance Foliated or Lamellar – layered structure, parts easily into very thin sheets CLEAVAGE HARDNESS  is an indication of how well a mineral break along these planes of weakness,  Hardness is a measure of how resistant and may be a good diagnostic a mineral is to scratching characteristic.  is controlled by the chemical  Cleavage may be described as composition and structure of the “perfect”, “good”, “distinct” or “poor”. mineral.  commonly measured on the Mohs QUARTZ scale  one of the most well-known minerals on earth.  the most varied of all minerals, occurring in all different forms, habits, and colors. PHYSICAL PROPERTIES OF QUARTZ CHEMICAL FORMULA - SiO2 COMPOSITION - Silicon Dioxide STREAK COLOR - Colorless, white, purple, pink, brown, and black.  The streak of a mineral refers to the colour of the mark it leaves behind after  Also, gray, green orange, yellow, blue, being rubbed against a piece of and red. Sometimes multicolored or unglazed porcelain. banded. LUSTRE STREAK - White  refers to the way in which the surface of HARDNESS - 7 a mineral reflects light, and is controlled CRYSTAL SYSTEM - Hexagonal by the kinds of atoms present and their bonding. Adamantine – diamond-like lustre; such minerals are usually transparent and have a high refractive index Dull or Earthy – no reflections  ROCK TYPE - Igneous, Sedimentary, Metamorphic POPULARITY - (1-4) 1 PREVALENCE - (1-3) 1 DEMAND - (1-3) 1 TRANSPARENCY - Transparent to opaque SPECIFIC GRAVITY - 2.6 – 2.7 LUSTER - Vitreous. Transparent, colorless Quartz crystals from a few distinct localities may be adamantine. CLEAVAGE - Indiscernible. Seldom exhibits parting. FRACTURE - Conchoidal TENACITY - Brittle OTHER ID MARKS 1) Some specimens fluoresce, especially white and green. 2) Triboluminescent. 3) Piezoelectric. COMPLEX TESTS - Dissolves in hydrofluoric acid IN GROUP - Silicates; Tectosilicates; Silica Group STRIKING FEATURES Hardness, crystal forms, striations on crystal faces, and frequent appearance of conchoidal fractures on crystal faces. ENVIRONMENT - Quartz occurs in almost every single mineral environment.  BIOTITE  Biotite is a very common form of mica  named in honor Jean Baptiste Biot (1774 - 1862), a French physicist Varieties MANGANOPHYLLITE - Manganese-rich variety of Biotite. MUSCOVITE  Muscovite is the most common mineral of the mica family  Muscovite is a very poor conductor of heat and electricity, and is thus used as an insulator for various electrical products and semiconductors. FELDSPAR Varieties  name of a large organization of  ALURGITE - manganese-rich, pink to rockforming silicate minerals that make red variety of Muscovite. up over 50% of Earth’s CRUST  FUCHSITE - dark green, chromium-rich AUGITE variety of Muscovite.  MARIPOSITE - green form of Muscovite  Augite is isomorphous with the minerals mica in small dense flake group found in Diopside and Hedenbergite Mariposa Varieties  SCHERNIKITE – a light pink form of Muscovite.  FASSAITE - has a low iron content; this  SERICITE – a fine-grained form of mica, is usually responsible for this variety usually Muscovite, that is somewhat having a lighter green color and silky in appearance. increased translucency then other most  STAR MUSCOVITE – describes Augite. twinned Muscovite crystals in pointed  JEFFERSONITE - varieties of Augite star-shaped sections. rich in manganese and zinc, found in the Franklin District,  URALITE – Pseudomorph of Actinolite after any mineral of the pyroxene group, especially Augite. HORNBLENDE  Hornblende is a group name used to describe Ferrohornblende and Magnesio-hornblende, but the term is generally more inclusive for all calcium aluminum amphiboles. CALCITE - Calcite is a rock-forming mineral GARNET with a chemical formula of CaCO3.  Garnet is the name used for a large group of rock-forming minerals. The common Garnets can be divided into two subgroups: Group 1: Garnets containing aluminum (Al) as their second element.These include Pyrope, Almandine, and Spessartine. ("Pyralspite") Group 2: Garnets containing calcium (Ca) as their first element.These include Uvarovite, Grossular, and Andradite. ("Ugrandite")