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EducationHow do rocks get named?
4th Mar 2012 14:09 UTCJason Evans
4th Mar 2012 15:34 UTCDavid Von Bargen Manager
4th Mar 2012 17:14 UTCMichael Kieron Expert
Anyway, rock classification is based on some systematics based on mineral content and there are ternary diagrams to give a reasonable (to a geologist) name to a rock. For example cumberlandite is technically just another magnetite melatroctolite based on the ratios of olivine, plagioclase, and pyroxene along with a large amount of magnetite.
Tanzanite and tsavorite may be mineral assemblages within the rock but I would not think of them as a rock type. I have rocks from an old copper mine with chalcopyrite, bornite, molybdenite, epidote and grossular but I would still call the rock a greenschist, maybe even an epidote greenschist.
From what I know, the rocks at Merelani are mostly dolomitic marbles and graphite gneisses and I would consider tanzanite/tsavorite as minerals hosted as veins and pockets within.
-Mike
4th Mar 2012 17:51 UTCJason Evans
4th Mar 2012 18:57 UTCDavid Von Bargen Manager
There are rock names such as granite, basalt, sandstone, schist, that have been used by geologists/petrographers for a long time. With a rock, you really need to have a lot of it (enough to qualify for mapping). Gemstone names tend to be coined to help sell something, either by adding adjectives to real minerals/gemstones (smoky topaz - really just smoky quartz) or trying to give it some cachet or suck up to someone (kunzite).
4th Mar 2012 22:57 UTCJason Evans
I am still curuious about what i can call my lavender jade from turkey, i have found out that the jade part of the rock is actually jadeite but i cannot call it jadeite as its only 40-50% jadeite so should i just call it a jadiete containing metamorphic rock? I'm sorry if i seem pedantic about these things but i just like to have things in my collection labeled correctly.
5th Mar 2012 01:02 UTCDon Saathoff Expert
Don
14th Apr 2012 09:19 UTCRalph S Bottrill 🌟 Manager
23rd Apr 2012 03:43 UTCMarco Jamer
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Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: March 28, 2024 19:38:11