Minerals for Geology

Hardness of 6. cannot be scratched by streak plate, Silicate Felsic,2 cleavages at ~90

Felsic, silicate, Hardness of 6 cannot be scratched by streak plate. 2 cleavages at ~90; often white to gray with striations

Felsic Silicate, Hardness of 2.5 i.e scratch with fingernail. Cleavage forms in sheets; light brown to colorless;

Mafic silicate; H-7 cannot be scratched by streak plate, Conchoidal fracture, no cleavage, forms small “sand grain” crystals, Green mostly

Mafic Silicate; H-5.5-6 can scratch glass/scratched with masonry nail or knife blade, 2 good cleavages at 87° and 93, short blocky prisms, dark green to black

Mafic Silicate H-5.5 can scratch glass/be scratched with masonry nail and knife blade, 2 good cleavage at 60° and 120°, dark gray to black, has needle-like prisms

Mafic Silicate; H-2.5-3 can be scratched with fingernail, 1 excellent cleavage forms sheets, black to brown-black

Felsic; non silicate; non metallic; H-3 can be scratched with a penny, 3 excellent cleavages at 75° to form rhombohedrons, colorless to white

Felsic; Non silicate; non metallic' H-3.5 can be scratched with little nail, 3 good cleavages not at 90° and often at 75° All colors, gray to white most common.

Felsic Non silicate, non metallic, H-2.5: scratched by fingernail; Clear; Tastes like salt. N

Felsic; Non silicate; non metallic; H-2 Cleavage good but variable between varieties; scratch w/ fingernail, transparent to white

Felsic; Non silicate; non metallic. H-1

Fools gold

Metallic H-2.5, good cleavage in 3 directions, silver gray, Very high Sp. Gr. Of 7.5

Metallic H-5-6, Color silver to gray to reddish; reddish brown streak