FMF - Friends of Minerals Forum, discussion and message board

[ezio bonsignore]

Hi, This is my first post, so I hope to do it right.

My wife of 50 years has a small collection of minerals, and from time to time I surprise her by adding some nice piece. In an auction site I have stumbled on something described simply as "red crystal," sipposedly out of Madagascar. My question: is this a real item, and if so what is it? Or, is it a manipulated calcite or quarz? or, is it plastic?
Many thanks in advance

[John Betts]

Looks like quartz coated with hematite or other iron oxide.

Search Google images for "quartz coated with hematite" and you will see many similar.

[ezio bonsignore]

Many thanks for your prompt clarification. Just to be sure I understand it correctly: is this hematite coating a natural process, or can it be artificially reproduced? For instance, the same seller also offers a much larger piece with this photo of the lower part. The fact that even the fracture surface, where the crystal was attached to the matrix rock appears to have a reddish coating looks like extremely suspicious to me. Or am I just paranoid?

[Bob Harman]

There are 2 questions here. First is your specimen from Madagascar and secondly is it entirely natural or has it, in some way, been altered/enhanced etc.
Firstly, looking at all the quartz examples on MinDat from Madagascar, I see a few examples of red, hematite included quartz, but yours would be, by far, the best photoed example so I am doubtful from that aspect.

Secondly your example is very red and quite evenly so. The second photo also shows the base, matrix area, to be too red. Taking all this together, I favor an enhanced or dyed quartz from some place like China rather than Madagascar.

To change my mind, I would have to see another similar quality and colored example that is all natural and from a known Madagascar locality. BOB

[Peter Megaw]

You are not paranoid....but even if you were that doesn't mean they're not out to get you.!

It is pretty easy to deposit a layer of iron oxide...read "rust" on almost anything and the fact that the coating here is very uniform and covers the broken matrix surface as well is indeed cause for concern. I suggest using your favorite search engine to search for Red quartz Madagascar images. You'll get a LOT and all of the ones I saw have a much less uniform coating.

If you still think you like it, ask the seller if it's real and if they take full cash back returns...

[ezio bonsignore]

1) The seller says "all natural," but of course this doesn't mean anything.
2) The seller says it is from Madagascar, but he is based in Singapore.

So, all considered I think I would rather pass on this one. Many thanks again for having saved me from a potential stupid buy.

[Tobi]

Hi Ezio,

like Bob and Peter suggested, this specimens seem to be dyed. I think they could really be from Madagascar (I guess Itremo Massif), but that colour does not occur naturally on Madagascan quartzes. There are some places in the world where really vivid red quartzes occur (e.g. Morocco, Namibia, South Africa), but pieces like that usually don't come from Madagascar. And I also agree with Bob and Peter that the matrix rock looks "too" red. Quite sure a faked specimen, sorry.

Regards
Tobi