Forums
New posts
Search forums
What's new
New posts
Latest activity
Members
Registered members
Current visitors
Charts
Log in
Register
What's new
Search
Search
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Gemstones, Minerals & Fossils
Gemstones and Minerals
Confirm Rock ID - Mica Schist on Calcite
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Help Support Prospecting Australia:
This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Message
<blockquote data-quote="user 4386" data-source="post: 290174" data-attributes="member: 4386"><p>I'm happy that it is a mica with felspar, quartz - a number of possibilities including weathered biotite, mixture with muscovite, phlogopite or rarer micas. Should snap back to a plane though if you just bend it 20 degrees (not enough to crack it). Some of the other physllosilcates are quite plastic - they stay wherever you bend them to, no matter how little.</p><p></p><p>I didn't realise that vinegar was sufficient for calcite. I always use 50% HCl because it distinguishes calcite and dolomite and magnesite (calcite disolves energetically in a flash, dolomite just fizzes slowly, magnesite not at all). Handy in lead-zinc exploration as often ore bodies occur regionally in limestone but ore fluids alter the calcitic limestone to dolomite near mineralisation, mangesite can be ore itself but often indicates evaporites nearby like gypsum and anhydrite, which can be ores but are also clues to lead, zinc, barite and fluorite in vicinity.</p></blockquote><p></p>
[QUOTE="user 4386, post: 290174, member: 4386"] I'm happy that it is a mica with felspar, quartz - a number of possibilities including weathered biotite, mixture with muscovite, phlogopite or rarer micas. Should snap back to a plane though if you just bend it 20 degrees (not enough to crack it). Some of the other physllosilcates are quite plastic - they stay wherever you bend them to, no matter how little. I didn't realise that vinegar was sufficient for calcite. I always use 50% HCl because it distinguishes calcite and dolomite and magnesite (calcite disolves energetically in a flash, dolomite just fizzes slowly, magnesite not at all). Handy in lead-zinc exploration as often ore bodies occur regionally in limestone but ore fluids alter the calcitic limestone to dolomite near mineralisation, mangesite can be ore itself but often indicates evaporites nearby like gypsum and anhydrite, which can be ores but are also clues to lead, zinc, barite and fluorite in vicinity. [/QUOTE]
Verification
Post reply
Gemstones, Minerals & Fossils
Gemstones and Minerals
Confirm Rock ID - Mica Schist on Calcite
Top