Answer:
Diamond-
Identifying characteristics:
Color- Colorless or White
Luster - adamantine
Streak - Colorless
Habit - Hourglass form
Hardness - 10
Cleavage - octahedral
Composition - pure carbon
Specific gravity - 3.5
Dolomite (CaMg(CO3)2)
Color - Colorless or White
Hardness ranging from 3 to 4
Reacts to acids
Gneiss
Distinct light and dark bands alternate
Biotite and pyroxene contribute to dark banding, being Mafic minerals
Quartz and feldspar provide light banding, being Felsic minerals
This is a high-grade metamorphic rock formed from the regional metamorphosis of lower grade rock.
Chalk (CaCO3)
Color - White
Extremely fragile
Hardness - 1
Fizzing occurs when it reacts with acid.
