Old classic. Sharp Augite crystals are uncommon from the volcanic deposits of Latium. A 1.7 cm, sharp, lustrous, prismatic, jet-black crystal is set on volcanic matrix.
Formula : (Ca,Na)(Mg,Fe2+,Al,Fe3+,Ti)[(Si,Al)2O6]
System: monoclinic Hardness:5½-6 Rarity:not common
Strunz id:VIII/F.1-90 -
SILICATES
Name origin: Named by Abraham G. Werner in 1792 from the Greek αυγή ("auge") for "shine" or "luster," in allusion to the appearance of its cleavage surfaces. The modern definition of augite is that it is relatively low in calcium with some disorder of occupancies of Fe2+ and Mg in both octahedral sites. Fe:Mg may vary from 0 to 1 by definition. Augites tend to have minor (up to 10 atomic percent) Na, Al, Ti, or Fe3+ substitution that also may be disordered in the M2 and M1 sites. The full Ca, ordered equivalent of augite is the diopside-hedenbergite series.-
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Specimen weight:195 gr.
Crystal size:i,7 cm long
Overall size: 100mm x 45 mm x 60 mm
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