Rhodonite? It might also be Rhodochrosite...? I've seen Rhodo's that color.
High RI, moderate birefringence , brownish-red pleochroism, typically showing cleavage planes inside of stone.
Just a slightly educated guess from a new GIA student!
Well, my references give a very large biref and, working on memory of the small number of each I've actually *viewed* the colour split under the dichroscope is right for Rhodonite but not Rhodochrosite. Others who have seen more may feel differently. But it's the biref that's the Rhodochrosite 'killer' I think.
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
Refractive Index of rhodochrosite is moderate: 1.680-1880 Birefringence is quite high: 0.020 But, indeed, it DOES occur in that color and has perfect cleavage.
BUT, RI and Birefringence knock it out of the competition.
Joined: Fri Oct 30, 2009 9:19 pm Posts: 590 Location: Las Vegas, NV
Kerensky wrote:
Stonebender wrote:
Rhodonite? It might also be Rhodochrosite...? I've seen Rhodo's that color.
High RI, moderate birefringence , brownish-red pleochroism, typically showing cleavage planes inside of stone.
Just a slightly educated guess from a new GIA student!
Well, my references give a very large biref and, working on memory of the small number of each I've actually *viewed* the colour split under the dichroscope is right for Rhodonite but not Rhodochrosite. Others who have seen more may feel differently. But it's the biref that's the Rhodochrosite 'killer' I think.
Hmm, I KNOW you knock me out of the park when it comes to this stuff, but I have to say my guess wasn't too bad for an amateur working from memory.
Hmmm.... if it's an inclusion it beats me. My guess is that it is an artefact - an optical illusion, if you prefer. But, if that is so, I don't know what it is that is being multiple-reflected.
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