Location, location, location
The legacy of lost labels
I’ve ranted about lack of labels for mineral specimens before. For many collectors, lack of location information condemns any specimen to the scrap heap.
But at the Butte Gem & Mineral Show last weekend here in Montana, I did something I sometimes do: I acquired a specimen with no information whatever.
The dealer had two categories of material: 1) high-end, and 2) maybe 100 flats of “Blow-Out Sale” items. The sale minerals included plenty of well-labeled specimens, and since I’m more of a mid-range, interesting/unusual/I don’t-have-one kind of collector rather than one who invests in some item worth more as a work of art than as a mineral, I had to go for a good number. At four for $10, you can hardly go wrong.
I found pretty purple coquimbite from Peru, sharp perovskite crystals perched on sharp magnetite crystals from Magnet Cove, Arkansas, and more to keep me entertained and educated. But for $2.50, I also couldn’t pass up the specimen in the top photo.
The dealer (whose inventory was world-wide albeit with a bit of a western US focus) had no idea where or even when he acquired it; it was one of many hundreds or thousands of things he’d been hauling around for years, and was ready to get rid of.
Despite no label, I’m sure it’s tremolite (or at least something in one of the series with tremolite). Tremolite is common enough, and radiating sprays like those in my specimen are also common enough, so a quick scan through MinDat photos of tremolite found nothing definitive. There’s a classic locality in Connecticut that’s similar, and others from Arizona (that have an apparently distinctive fluorescence, that mine lacks), but there are really too many tremolite occurrences around the world to narrow it down much.
The piece also has tiny (mostly less than 1 mm) transparent brown mica crystals (probably biotite or phlogopite) and the tremolite rests on a substrate that includes calcite, no surprise since tremolite is a calcium-magnesium silicate that often forms when limestones and dolomites (calcium and magnesium-calcium carbonates, respectively) are metamorphosed. Again, not much help regarding a locality.
Nonetheless, I don’t have the slightest regret at spending that $2.50 for something whose source I may never know. It was just too cool to pass up, and you never know, someday I may encounter another example.
Or maybe one of you will recognize it and share the locality!
I feel your pain. I too have a dozen or more unlabeled but "very nice" specimens that one day I hope to link to an, as yet, unknown locality. I've managed a couple so far but it certainly keeps the brain active. Some years back I was given some "blue obsidian" from Queensland that appeared pretty suspect, but I tucked it away "just in case". Earlier this year I spilt a pile of old geo off prints and saw a paper on "blue obsidian from Geelong, Victoria". This actually was a paper reassigning it to tactylite and appeared to match the specimens I had. Still looking into it as the blue tachylite from Queensland does exist but the material from Victoria (collected pre 1900) may not.
The purple coquimbite was worth it all in my opinion Richard! Nice haul!... I saw that in one of the mineral magazines and thought : too cool! Some minerals just 'strike me' and I want one, ( like whewellite) but if it'll ever happen is another thing. I hope you enjoy it immensely.