Rock-Forming Minerals PDF

Rock- Forming Minerals Seeing Rocks from Within  To Start… Main Idea: Minerals are the building blocks of rocks Essential Question: What are the physical and chemical properties of minerals?  What are Minerals? Minerals are composed of Elements. Elements found in the periodi...

Rock- Forming Minerals Seeing Rocks from Within  To Start… Main Idea: Minerals are the building blocks of rocks Essential Question: What are the physical and chemical properties of minerals?  What are Minerals? Minerals are composed of Elements. Elements found in the periodic table Abraham Werner (1771-1800): Father of Mineralogy; classified minerals Abraham Werner (1771- 1800): Father of Mineralogy; classified minerals  Common Characteristics of Minerals Minerals are… Naturally- occurring chemical compounds Inorganic (without presence of Carbon) Homogeneous Solids (with uniform composition) With a definite chemical composition (yielding chemical formula) Arranges atoms in crystalline pattern Minerals made up of only one element Gold Graphite Diamond Copper  Let us Differentiate the Physical Properties of Minerals Namely: Luster Color Streak Hardness Cleavage Fracture Specific Gravity  Luster Quality of light on the surface of a rock, crystal or mineral High Luster = Very Reflective Mineral Further Description: Greasy, Silky, Metallic, Earthy (suggestive of nature) and Vitreous (glassy)  Color Caused by either absorption or lack thereof of visible light. Minerals have color in various hues. Hard to distinguish using mere color.  Streak Color of powdered mineral produced when a mineral is rubbed across an unweathered surface. Used to distinguish between metallic and nonmetallic minerals.  Hardness Minerals’ ability to resist scratching or abrasion. Unknown versus known Mohs Scale of Hardness (1 as softest, 10 as hardest)  Cleavage Tendency of a mineral to split or cleave along planes of weakness. Bonds between atoms are the weakest at planes in which cleavage occurs. Defined break (good cleavage) versus Not Defined (poor cleavage)  Specific Gravity Measure of relative density of a mineral Comparing to relative mass to water Specific gravity= mass of mineral/ mass of equal volume of water  Specific Gravity Measured also using Archimedes’ Principle. Specimen weighs less when immersed in water than in air. Specific gravity= weight of mineral in air/ weight in air minus weight in water