from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A brownish-bronze, lustrous copper ore with the composition Cu5FeS4 that tarnishes to purple when exposed to air.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A reddish mineral that tarnishes on exposure to air; it is a mixed sulfide of iron and copper with the chemical formula Cu5FeS and is an important ore of copper.
from the GNU version of the Collaborative International Dictionary of English
- n. A valuable ore of copper, containing copper, iron, and sulphur; -- also called purple copper ore (or erubescite), in allusion to the colors shown upon the slightly tarnished surface.
from The Century Dictionary and Cyclopedia
- n. A valuable copper ore, consisting of about 60 parts of copper, 14 of iron, and 26 of sulphur, found mostly massive, also in isometric crystals.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. a mineral consisting of sulfides of copper and iron that is found in copper deposits
~ Much of the copper of commerce is made from chalcopyrite and bornite, and these ores are more difficult to work.
In the easy recognition of the secondary copper sulphides, chalcocite, bornite, etc., the engineer finds a finger-post on the road to extension in depth; and the directions upon this post are not to be disregarded.
Other minerals of considerable importance in some districts are chalcopyrite and bornite
The ore is chiefly chalcocite and bornite in quartz, and occurs in lenticular veins, from a few inches to 14 feet in thickness.
The mineralization at Talpas consists of coarsely crystalline dark sphalerite and galena with pyrite, chalcopyrite and minor bornite in markedly silicified, fine-grained, thinly laminated, cherty sedimentary rocks that occur below a thick pile of quartz-porphyritic rhyolite flows.
The exposed mineralization consists primarily of malachite, chalcopyrite, pyrite and magnetite, with minor bornite and possibly chalcocite.
Within the corridor various historic production and exploration workings have encountered and locally exploited massive chalcopyrite plus chalcocite plus pyrite and/or bornite sulphide mineralization.
The copper mineralization within the upper 300 metres of the deposit includes both supergene digenite-covellite and hypogene chalcocite-bornite replacing earlier chalcopyrite.
Specifically, most of the gold and copper discovered so far at La Cantera are spatially associated with quartz-magnetite-chalcopyrite+/- bornite veinlets in potassic altered porphyry and breccias containing elevated quantities of hydrothermal magnetite.
In DDH DOT-09-NW-06, trace native copper, chalcopyrite and more abundant bornite occur in thin quartz-hematite veinlets in granodiorite exhibiting moderate to strong argillic and potassic alteration.