Rock
Name
Rock Type:
Igneous
Sedimentary
Metamorphic
Observed I. D. characteristics, general description, and economic use* 8 Pumice Igneous Porous, flats, Hardness 3, streak White, Greenish White or Grey, economic use, used for emery boards, hand soap, and some cleaning materials.
9
Obsidian
Igneous
Glassy, black in color, Hardness of 5. economic use, Used for early hunting tools and weapons.
10
Scoria
Igneous
Coarse grain, Hardness 6, bubble like cavities, vesicular, economic use, used for decoration and the cement industry.
11
Basalt
Igneous
Hardness 6, fine grained, massive, dark gray in color. Streak grey to white, economic use, used for whetstones, paving, and building supplies.
12
andesite
Igneous
Hardness 7, fine grained, bluish gray. Dull, economic use, used for roof tiles.
13
Granite
Igneous
Hardness 7, economic use, used for countertops.
14
Rhyolite
Igneous
Hardness 6, gray, porphyritic, economic use, used as decorative aggregates, building stone.
15
Limestone
Sedimentary
Color variable, but generally light colored, grey through yellow. Hardness of 3-4, no cleavage, economic use, Used for production of glass, paper 16 Slate Metamorphic Fine grained, foliated, Hardness 5, dull luster, economic use, used in bathrooms and garden decoration * See Chapter Two and other sources Specimen NumberRock Identification Student Name:
Rock Name
Rock Type:
Igneous
Sedimentary
Metamorphic
Observed I. D. characteristics, general description, and economic use* 17 Quartzsite Metamorphic White to gray in color, hardness of 7, coarse texture, conchoidal fracture. economic use, Used as early large cutting tools.
18
Gneiss
Metamorphic
Banded, foliated, layered, Hardness 7, economic use, used for decorative stone countertops, monuments, and facings.
19
Talc Schist (Soapstone)
Metamorphic
White, beige, gray, yellow, brown, pink, purple, blue, green. Rarely colorless soft. Hardness 1, economic use, used as...
