Feldspar Gems Updated

Sounds like either Andesine or Labradorite - it's in the range for either. Your stone appears to have some silk and/or or schiller inclusions, which can distort the reading one way or the other.

The difference between the two is not based on RI, however, but rather on the quantity of Calcium present.

Your stone looks like a green Labradorite containing red copper Schiller highlights. Yes, it is rare, whether it turns out to be Andesine or Labradorite. Nice size, too. I've seen similar examples from Oregon sources. But also some similar said to be from sources in the Congo, Tanzania, Mongolia and Tibet (other than Oregon, no deposits have ever been confirmed by independent geologists, however). The market is currently getting so confused by the misinformation being put about by TV and other hucksters, that prices vary widely.

Gem-grade, transparent, facetable, copper-colored Labradorite or Andesine used to all be lumped together under the category of "Oregon Sunstone" (that being the only source). But some marketers seem to be confusing these colored Labradorite and Andesine stones from Oregon with the entirely different Oligoclase "Sunstones," and insisting that Schiller somehow defines an "Oregon Sunstone" (which it does not). The terminology is consequently becoming a mess.

Collectors like the rarer greens, but reds usually fetch higher prices in jewelry. Greens which tend towards blue are more sought after than brownish greens. Collectors also like stones that are strongly dichroic or trichroic.

Hope that helps.

I noticed that there are several unusually large stones being sold. Assuming that the gems have been correctly identified, it would seem that one of the mines must have hit a pocket of larger crystals. That happened a couple of years ago, and you could find 8-15 ct. stones at reasonable prices for a few weeks. The stones weren't particularly well cut, and in many there were inclusions and dull silk. But I picked one up, just because large Labradorite and Andesines aren't particularly common. Then the supply of "bargain" stones dried up, leaving only those which were $100/ct. and upwards.

These Feldspars have perfect cleavage in 2 directions. That means that the crystals tend to shatter when exposed to blasting or hammering during mining. That also causes crystals which get washed into streams to quickly erode into tiny fragments (except in desert locations, where large crystals can be found on the surface of the ground). So, while large crystals do exist in nature, getting them out of the hard rock in which they grow results in few surviving ... just a bit more trivia I've accumulated.

Hi I have a hobby gold mine in Eastern Oregon and I am always finding gemstones. They range in size from (most of then) a grain of sand to about the size of a pea. Most of them are red some are orange. Do uncut stones have any value? Any info is appreciated.

Thanks

Roger

Sorry Roger, got cut off. Meant to add that mineral specimen collectors look for interesting crystal structure, unusual colors, complete faces on the crystals, multiple crystals, and other interesting features.

If you intend to try and sell your pieces, you'll want to state the location found, and list in either the Jewelry and Watches/Loose Diamonds and Gemstones category (if you think faceters and cabbers will be interested) or in the Collectibles/Rocks, Fossils/Minerals category (if primarily of interest to mineral specimen collectors) - or both.

You would need to know what sort of gems you have found. Your raw Gold ore can also fetch good prices in the same two categories. Gold ore is sometimes used as a gemstone, and interesting pieces are valued by the mineral collectors. Wish I had a "hobby gold mine in Eastern Oregon" - that's very cool!

If you wish, you could open a free account at www.photobucket.com and put your photos there. Then just post a link to the picture or album.

What may also be even more help would be to contact the Geology Dept. at Eastern Oregon University. You could email one of the staff with the link to your pictures. You can find staff (along with some of their email addresses) by going to their website at http://www.eou.edu/~geology/ - they might want to be mailed a sample for testing.

It really sounds interesting. The sunstones from elsewhere in Oregon contain Copper, and they really aren't associated with Gold mining areas. Who knows, you might have something entirely new there.

Your stones are absolutely fabulous! Your photos are very graphic and easy to see your descriptions of the stones. Thanks for the show, I will return for more, dinner is ready! smiles, frstyfrolk/Cyndi