Freshly broken bornite is brown ( tarnishes in a few days to bluish grey) whereas freshly broken chacolcite is dark bluish grey. This sample comes from the Bethlehem copper porphyry deposit in the Central Interior. The scientific study of the origin, history, and structure of the Earth.
Large-scale open pit mining started at Bethlehem in 1962 and continued until the early 1980s, when production shifted to the other deposits, which are still being mined today. Early prospectors found copper mineralization in the Highland Valley area in the late 1800s and started hand mining at the Snowstorm and Iona zones of the Bethlehem deposit in 1907, when a wagon trail was built to nearby Ashcroft and the Fraser Canyon railway line. A way to tell the difference between bornite and acid-treated chalcopyrite is to use a streak plate; bornite streaks dark gray and chalcopyrite streaks a green tinged black. It is also known as peacock ore because of its iridescent purple-blue-green tarnish. It is most likely bornite given the prevalence of the the peacock tarnish. How deep into chalcopyrite does the tarnish extend? A characteristic deep brass yellow colour and iridescent green-to-purple weathering surfaces distinguish chalcopyrite from gold and sulphides such as pyrite. This is a question that is going to come up again and again.
Current server date and time: November 26, 2020 06:47:07, http://rruff.info/doclib/cm/vol18/CM18_173.pdf. Chalcopyrite Vs Bornite. The first is probably as Stephanie said treated Chalcopyrite, however the second may be Chalcocite. bornite | chalcopyrite | As nouns the difference between bornite and chalcopyrite is that bornite is while chalcopyrite is (mineral) a yellow mineral that is a mixed sulfide of copper and iron, with the chemical formula cu]]fe[[sulfur|s 2. While we are at it, would someone write an article about how to test for carbonates, acid testing etc.? Naturally colorful chalcopyrite can be found but it is much rarer, I know that in the silver deposits of Ontario chalcopyrite that has tarnished bright blue is an indicator of Silver. From 1962 to 1982, production at the Bethlehem mine totalled 96,324,510 tonnes of ore that yielded 99,826,893 grams silver, 1,279,833 grams gold, 398,112,545 kilograms copper and 851,048 kilograms molybdenum. Bornite is only relatively briefly colorful and eventually turns black which chalcopyrite will not do. Fresh bornite, however, is copper red. The large Valley pit and operations are visible from a lookout on Highway 97C. The ore minerals are mainly in very narrow veins, often only a few millimetres wide. Different formulas and different crystal systems. Bornite is an important copper ore mineral found in many different types of copper deposit. I’ll try the streak part. Most of the "peacock ore" they sell is treated chalcopyrite probably because it stays colorful a lot longer ( indefinitely) and is cheaper to buy than bornite. Don't recall seeing blue chalcopyrite. chalcopyrite. Do you have a photo of the fresh cut surface you can show us, to someone familiar with bornite and chalcocite the difference is obvious but to someone new it may not be.
You will need to break a corner off to find out. Now that you pointed that out, I would say it is chalcocite. Chalcopyrite is also found as fine “disseminations”, or speckles, throughout the host granodiorite rock. The deposit is about 15 km west of the small town of Logan Lake, and about 80 km southwest of Kamloops. Here is a paper that discusses this relationship between silver and tarnished chalcopyrite: Would someone take it upon them selves to write an article about peacock ore and iridescence in general? As nouns the difference between covellite and bornite is that covellite is mineral a shiny indigoblue sulfide mineral, cusulfurs, that is an ore of copper while bornite is. This is despite having a relatively low copper yield (only 25% of its atoms are copper) compared to other copper minerals such as chalcocite and cuprite (both with 67% yields), or bornite and covellite (that have 50% yields). Chalco comes from the Greek word chalko, meaning copper. Fresh bornite, however, is copper red. The Bethlehem deposit is one of the deposits that make up the Highland Valley Copper mine, which also includes the Lornex, Highmont and Valley deposits. It is also known as peacock ore because of its iridescent purple-blue-green tarnish. Bornite is only relatively briefly colorful and eventually turns black which chalcopyrite will not do. Bornite vs Chalcopyrite - What's the difference? Press J to jump to the feed. Chalcopyrite - CuFeS2 - tetragonal Bornite - Cu5FeS4 - orthorhombic. Press question mark to learn the rest of the keyboard shortcuts, Experimental Petrology : Exploration Geology. this being said, proper chalcopyrite would be a noticeable brassy color, and oftentimes proper untarnished bornite … However, the chalcopyrite you see that looks like bornite has been treated with acid (it is more common than bornite and is often sold as bornite, so be wary of scams). As for museums being correct in their identification of what they sell in their shops, they are only as correct as their suppliers which in most cases is very questionable and in many cases just plain wrong. Throughout human history, chalcopyrite has been our leading source of copper. However, the chalcopyrite you see that looks like bornite has been treated with acid (it is more common than bornite and is often sold as bornite, so be wary of scams).