Mineral Identification Lab Answers
Question: Calcite (1)
Answer: Comes in many white colorsWhite streakHardness = 33 directions of cleavage not at 90 degreesNonmetallic-glassy lusterReacts to HCl
Question: Quartz (2)
Answer: Many light colorsNo streakHardness = 7Conchoidal fractureNonmetallic-glassy lusterLarge crystals are elongate and may have 6 facets but are not cleavage planes
Question: Garnet (3)
Answer: Deep reddish purpleNo streakHardness = 8Conchoidal fractureNonmetallic-glassy lusterWell-formed crystals are spherical with many facets that are not cleavage planes
Question: Amphibole (4)
Answer: BlackGreenish-black streakHardness = 62 cleavages not at 90 degreesNonmetallic-glassy luster
Question: Pyroxene (5)
Answer: Much like amphibole in its physical propertiesDiffers mainly in cleavage: 2 cleavages at 90 degrees
Question: Olivine (6)
Answer: Olive green colorNo streakHardness = 6Conchoidal FractureNonmetallic-glassy lusterTiny grains, need hand-lens
Question: Muscovite Mica (7)
Answer: Silver or golden when in thick sheetsClear when in thin sheetsWhite streakHardness = 2One excellent cleavageNonmetallic-glassy or plastic-like
Question: Biotite Mica (8)
Answer: Brown or dark greenBrownish or greenish streakWhite streakHardness = 2One excellent cleavageNonmetallic-glassy or plastic-like
Question: Feldspar, K-rich (9)
Answer: Pinkish colorNo streak Hardness = 62 cleavages at 90 degreesNonmetallic-glassy luster
Question: Feldspar, Na- and Ca-rich (10)
Answer: White samples are Na-richDark samples are Ca-richHardness = 62 cleavages at 90 degreesNonmetallic-glassy luster
Question: Talc (11)
Answer: Many (usually light) colorsWhite streakHardness = 1One poor cleavageNonmetallic-pearly lusterThe source of talcum power
Question: Pyrite (12)
Answer: Brass yellow colorDark streakHardness = 6 (varies)Conchoidal fractureMetallic lusterSome samples have cubic crystalsOre is made of iron and sulfurFool's gold
Question: Chalcopyrite (13)
Answer: Greenish brass yellow colorDark streakHardness = 4 (variable)No cleavage and no crystalsMetallic lusterOre contains iron and sulfur plus copper (chalco means copper)Fool's gold
Question: Sphalerite (14)
Answer: Brownish colorYellow streakHardness = 3.5-4Many cleavages at various anglesNonmetallic "resinous" or metallicContains zinc, iron, and sulfur
Question: Galena (15)
Answer: Dark grey Dark streakHardness = 5-63 cleavages at 90 degrees (called cubic cleavage)Metallic lusterUnusually heavyLead ore, contains lead and sulfur
Question: Hematite (16)
Answer: Red, black, and silvery varietiesRed-brown streakHardness = 5-6No cleavageMetallic lusterIron ore, contains iron and oxygen