Table of Contents Section 3: Uses of MineralsUses of Minerals Section 1: Minerals Section 2: Mineral IdentificationMineral Identification Chapter: Minerals

A. Physical Properties— Mineral Appearance 1. Color and appearance are two obvious clues that can be used to identify minerals. 2. Some other properties to study include how hard a mineral is, how it breaks, and its color when crushed into a powder. Mineral Identification 2 2

B. Hardness 1. A measure of how easily a mineral can be scratched is its hardness. 2. Sometimes the concept of hardness is confused with whether or not a mineral will break. Mineral Identification 3. It is important to understand that even though a diamond is extremely hard, it can shatter if given a hard blow in the right direction along the crystal. 2 2

C. Mohs Scale 1. In 1824, the Austrian scientist Friedrich Mohs developed a list of common minerals to compare their hardnesses. 2. This list is called Mohs scale of hardness. Mineral Identification 2 2

D. Luster 1. The way a mineral reflects light is known as luster. 2. Luster can be metallic or nonmetallic. Mineral Identification 3. Minerals with a metallic luster shine like metal. 2 2

D. Luster 4. When a mineral does not shine like a metal, its luster is nonmetallic. 5. Terms for nonmetallic luster include dull, pearly, silky, and glassy. Mineral Identification 2 2

E. Specific Gravity 1. Minerals also can be distinguished by comparing the weights of equal-sized samples. 2. The specific gravity of a mineral is the ratio of its weight compared with the weight of an equal volume of water. Mineral Identification 3. Specific gravity is expressed as a number. 2 2

F. Streak 1. When a mineral is rubbed across a piece of unglazed porcelain tile, a streak of powdered mineral is left behind. Mineral Identification Streak is the color of a mineral when it is in a powdered form.

F. Streak 3. The streak test works only for minerals that are softer than the streak plate. 4. Some soft minerals will leave a streak even on paper. Mineral Identification 5. The last time you used a pencil to write on paper, you left a streak of the mineral graphite. 2 2

G. Cleavage and Fracture 1. The way a mineral breaks is another clue to its identity. 2. Minerals that break along smooth, flat surfaces have cleavage (KLEE vihj). Mineral Identification 3. Cleavage is determined partly by the arrangement of the mineral’s atoms. 2 2

G. Cleavage and Fracture 4. Not all minerals have cleavage. 5. Minerals that break with uneven, rough, or jagged surfaces have fracture. Mineral Identification 6. Quartz is a mineral with fracture. 2 2

Question 1 Minerals The Mohs scale uses __________ to compare minerals. A. cleavage B. color C. hardness D. luster 2 2

Question 2 Minerals Minerals that break easily along smooth, flat surfaces have __________. A. cleavage B. fracture C. luster D. streak 2 2

Question 3 Minerals Which of the following minerals will pick up iron filings? A. calcite B. feldspar C. lodestone D. quartz 2 2

End of Chapter Summary File