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MINERAL NAME, FORMULA | |
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BLACK to DARK GREEN color; EXCELLENT 2-WAY CLEAVAGE, not at right angles; H=5-6. | HORNBLENDE,
NaCa2(Mg,Fe,Al)5(Al,Si)8O22(OH)2 |
| BLACK to DARK GREEN color; Good to poor 2-way cleavage, at right angles; H=5-6. | AUGITE,
Ca(Mg,Fe)Si2O6 |
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| BLUE-BLACK to DARK GREENISH GRAY color; 2-way, right angle cleavage; STRIATIONS on some cleavage faces; H=6. | PLAGIOCLASE
FELDSPAR, (Ca,Na)(Al,Si)4O8, Ca>Na |
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| PISTACHIO-GREEN, yellowish green, dark green color; H=6-7; CLEAVAGE MAY BE DIFFICULT TO OBSERVE. | EPIDOTE,
Ca2FeAl2Si3O12(OH) |
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| RED, BROWNISH RED, NEARLY BLACK color; H=6.5-7.5; NOT TRUE CLEAVAGE, ALMOST FLAT SURFACES ARE "PARTING." | GARNET,
(Fe,Mg,Ca)3Al2Si3O12 |
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