Observed I. D. characteristics, general description, and economic value or use* # 1 Microcline/ Orthoclase Feldspar Rock- forming Hardness 7, cleavage at 90 degrees, white streak, vitreous. economic use, used in porcelain production.
Hardness 6, 2 directions of cleavage, white streak, striations, vitreous, economic use, used for porcelain as well.
Hardness 5-6, opaque greenish-brown, economic use, used for highway construction.
Glassy, transparent, hardness 3, perfect cleavage, economic use, used for window panes in the 1700's.
Hardness of 3, black in color, brittle, sheets. economic use, used to find ages of rocks.
Hardness of 3, reacts to mild acid. economic use, used for pharmaceuticals, construction, and agricultural soil treatment.
Hardness of 7, opaque, white in color. economic use, used for decoration.
White to colorless, three directions of cleavage at 90 degrees, salty taste, Hardness 2. 5, economic use, used in the winter on roads to control the accumulation of snow and ice.
Brass yellow, generally an aggregate of cubic, Hardness 6, greenish-black streak economic use, Pyrite used to be an important ore for the production of sulfur and sulfuric acid, the most important use of pyrite is as an ore of gold.
* See Chapter One and Appendix B Specimen Number Mineral Name Category:
Observed I. D. characteristics, general description, and economic value or use* 32 Limonite Ore Yellow brown to dark brown, Hardness variable (1-3) earthy appearance, powders easily, yellow brown streak economic use, it has been one of the most important pigments for creating paints in the yellow to brown color range known as ocher. Its use as a pigment continues today.
Green, streak green, Hardness (3. 5-4) economic use, the mineral malachite is an excellent material for producing a powdered pigment because it can easily be ground into a fine powder, it mixes easily with vehicles, and it retains its color well when exposed to light over time. It is also used in making beads for jewelry.
Golden Yellow, Hardness 4, greenish-black streak economic use Chalcopyrite has been the primary ore of copper since smelting began over five thousand years ago.
Yellow, Hardness 1-2. 5, cleavage not prominent, economic use, used in the vulcanisation of black rubber, as a fungicide, and in black gunpowder. Most sulfur is, however, used in the production of sulfuric acid.
Silvery gray, Hardness 2. 5, cubic cleavage, gray-black streak, economic use important mineral because it serves as an ore for m...