Mineral properties and Identification
Which statement best describes the hardness of the mineral dolomite?
Dolomite can scratch a copper penny but cannot be scratched by a fingernail
Which statement about the mineralsplagioclasefeldspar, gypsum, biotite mica,and talc can best be inferred from your lab research?
These minerals all exhibit cleavage
Carbonate minerals bubble with acid because they have CO3 as partof their chemical composition. Which minerals willreact with acid becausethey are carbonates?
Calcite and dolomite
If a quartz crystalhas a mass of 6g what is its volume?
2.64 cm3
A sample of gypsumhas a volume of 12 cm3. What is its mass?
26.4 g
What is the difference between a mineral that has cleavage and one that has fracture?
Cleavage is a regular, predictable breakage along internal or crystal structures, fracture is random
Quartz is one of the main components of most beach sand. What property ofquartz allows it to survive transport by waves and rivers over long distances?
Hardness(some people put "insoluble in water,"but that is kind of a given!)
The internal atomic structure of a mineral most likely determines the mineral's
Hardness, cleavage, and crystal shape
Why is it not possible to identify minerals using color alone?
Many minerals with the same chemistry will have different colors depending on impurities and crystal structure
Which mineral will scratch glass (hardness = 5.5), but not pyrite?
Orthoclase
Thetablebelowshows some observed physical properties of a mineral. Based on these observations, and the chemical data from your textbook, the elements that make up this mineral's composition are
Oxygen, silicon, hydrogen, and magnesium (Talc!)
Which mineral scratches dolomite and is scratched by olivine?
Potassium feldspar
Which property best differentiates plagioclase feldspar and orthoclase feldspar?
Striations
Which property could you use to tell the difference between talc and graphite?
luster
A colorless mineral has been found with a mass of 11.2gand a volume of 4ml. According to the chart above, what is this mineral?
muscovite
Which mineral leaves a green-blackpowder when rubbed against a porcelain plate?
pyrite
