Scientific Definition Minerals are I Naturally occurring II

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Scientific Definition Minerals are…. . I. Naturally occurring II. Inorganic III. Solids IV. With

Scientific Definition Minerals are…. . I. Naturally occurring II. Inorganic III. Solids IV. With definite chemical compositions, V. And ordered atomic structures

Minerals are economically important http: //www. mii. org/

Minerals are economically important http: //www. mii. org/

Formation of minerals Anything that changes from liquid to solid forms crystals (not just

Formation of minerals Anything that changes from liquid to solid forms crystals (not just “rocks”) • Snow flakes are crystals • Sugar and salt are crystals • http: //www. youtube. com/watch? v=czm. Q 2_ym a. Oo

Physical Characteristics include. . . • Color **Note that • Luster size is not

Physical Characteristics include. . . • Color **Note that • Luster size is not a • Fracture/Cleavage physical • Streak characteristic • Hardness • Specific Gravity

Color • Color of some minerals is a very useful characteristic to use in

Color • Color of some minerals is a very useful characteristic to use in identifying them. • Sometimes it is not • This sulfur for example is almost always yellow. • Quartz can be almost any color

• Luster is the way in which a mineral reflects light, or the

• Luster is the way in which a mineral reflects light, or the way that it shines. Luster may be “Metallic”. . . Or Non Metallic • If it looks shiny like metal, its metallic

This is the metallic luster of the mineral Galena

This is the metallic luster of the mineral Galena

Or it may be “non-metallic” • Non-metallic mineral luster’s include such descriptions as earthy,

Or it may be “non-metallic” • Non-metallic mineral luster’s include such descriptions as earthy, glassy, dull, or silky.

Or Earthy like

Or Earthy like

• Streak is the color of the powder left behind when the mineral

• Streak is the color of the powder left behind when the mineral is rubbed on a piece of unglazed porcelain.

• Hardness is a mineral’s resistance to being scratched. • NOT ITS RESISTANCE

• Hardness is a mineral’s resistance to being scratched. • NOT ITS RESISTANCE TO BREAKING!!! • A numerical scale from 110 is used to measure hardness. (Moh’s Scale) • Talc is the softest mineral at #1. • Diamond is hardest (#10)

• Specific gravity is the ratio of a mineral’s mass compared to an

• Specific gravity is the ratio of a mineral’s mass compared to an equal volume of water. In other words, how many times heavier is the mineral than the same amount of water? (a. k. a. Density)

• is the way in which a mineral breaks. If the mineral breaks

• is the way in which a mineral breaks. If the mineral breaks along smooth flat surfaces like calcite or mica, it is said to cleave.

• Some minerals break along parallel planes of weakness • This is due

• Some minerals break along parallel planes of weakness • This is due to the internal arrangement and bonding of their atoms. • http: //www. youtube. com/watch? v= iafah. Wbr. K 5 Y (5 min) in.

• Fracture refers to the characteristic of breaking along rough irregular surfaces. Mineral

• Fracture refers to the characteristic of breaking along rough irregular surfaces. Mineral like quartz and garnet are said to “fracture”. Think of a meat cleaver and a bone fracture to keep these terms straight.

• These properties of mineral crystals are determined by • 1. It’s chemical

• These properties of mineral crystals are determined by • 1. It’s chemical make-up • 2. the arrangement of its atoms.