PHYSICAL PROPERTIES | MINERAL NAME, FORMULA |
|---|---|
| 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 |
| 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, where Ca>Na |
| PISTACHIO-GREEN, yellowish green, dark green color; H=6-7;CLEAVAGE MAY BE DIFFICULT TO OBSERVE. | EPIDOTE, Ca2FeAl2Si3O12(OH) |
| RED, BROWNISH RED, NEARLY BLACK color; H=6.5-7.5; NOT TRUE CLEAVAGE, ALMOST FLAT SURFACES ARE "PARTING." | GARNET, (Fe,Mg,Ca)3Al2Si3O12 |
