Pretty rock of the day: Pentagonite
Sep. 15th, 2011 04:19 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
stephbgI haven't encountered Pentagonite before, possibly because decent specimens appear to be wildly out of my price range. But on spec I was browsing for micro minerals on ebay and came across this little beauty: ROYAL BLUE PENTAGONITE ON MICRO HEULANDITE MATRIX. Apologies for the shouting but rock dealers tend to wax enthusiastic about their products. I'm not sure if that ebay link will survive forever.
Firstly Heulandite, the stuff the pentagonite is growing on:
And now the pentagonite itself, as taken by the camera:
In life the colour has a more greenish tinge that makes it closer to teal, but I haven't yet managed to get my lighting and white balance set up to my satisfaction. In person it doesn't look quite so much like copper sulphate, and now I go looking it doesn't have any copper in it at all: Ca(VO)Si4O10•4(H2O). Hello Vanadium. It doesn't look much like its relative vanadinite either.
I won this piece at auction for about a tenth of what I'd have guessed its value from previous sales. I was quite surprised to win it, because my top bid wasn't anywhere near the assumed value.
But I was lucky and ended up being the only bidder.
Of course my valuation might be way off; this specimen rather unsurprisingly has been damaged in its lifetime, and perhaps the more expensive ones are in more pristine condition. But holy crap Batman, I've just done a bit of googling and found more evidence that I've got myself a MAJOR bargain. Check out some of these. Mine's at least as nice looking as one priced at $475. What did I pay, including postage and excellent handling? USD$26! And that site claims to have significantly cheaper prices than other dealers. Whoa. The advantages of buying from the source! Pune, India, if you're curious.
Under the microscope:
Even if it's an "inferior" specimen I think it's pretty and well worth the price I paid.
It came from India, in truely impressive packaging. It seems to have become commercially available only about 30 years ago.
It's not the sort of thing you can just chuck in a postpack.
No Art today, just pictures of a pretty thing.
Firstly Heulandite, the stuff the pentagonite is growing on:
And now the pentagonite itself, as taken by the camera:
In life the colour has a more greenish tinge that makes it closer to teal, but I haven't yet managed to get my lighting and white balance set up to my satisfaction. In person it doesn't look quite so much like copper sulphate, and now I go looking it doesn't have any copper in it at all: Ca(VO)Si4O10•4(H2O). Hello Vanadium. It doesn't look much like its relative vanadinite either.
I won this piece at auction for about a tenth of what I'd have guessed its value from previous sales. I was quite surprised to win it, because my top bid wasn't anywhere near the assumed value.
But I was lucky and ended up being the only bidder.
Of course my valuation might be way off; this specimen rather unsurprisingly has been damaged in its lifetime, and perhaps the more expensive ones are in more pristine condition. But holy crap Batman, I've just done a bit of googling and found more evidence that I've got myself a MAJOR bargain. Check out some of these. Mine's at least as nice looking as one priced at $475. What did I pay, including postage and excellent handling? USD$26! And that site claims to have significantly cheaper prices than other dealers. Whoa. The advantages of buying from the source! Pune, India, if you're curious.
Under the microscope:
Even if it's an "inferior" specimen I think it's pretty and well worth the price I paid.
It came from India, in truely impressive packaging. It seems to have become commercially available only about 30 years ago.
It's not the sort of thing you can just chuck in a postpack.
No Art today, just pictures of a pretty thing.
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no subject
Date: 2011-09-15 09:37 am (UTC)no subject
Date: 2011-09-15 01:32 pm (UTC)