Re: Gem Silica
Ahh, the age ole, "what is gem silica worth?" And classic, confusion as to what gem silica is. In a nut shell, true gem silica should have less than 5-10% inclusion. It is a chalcedony,(think fine green chrysoprase, except turquoise blue) and is very hard stuff. Unlike similar chrysocolla in quartz, or Chrysocolla Silicate. both which are hard, take a nice polish, but are not Gem silica. And are flooded into the market by the ignorant calling it gem silica simply because its a hard blue stone. Gem silica should be like Gel, very transparent, but in some cases the inclusions of blue color is very dense, which Inpersation material was well known for. These tend to be like blue jasper, not transparent, except on the edge were the silica is often cut thinner than the table.
As far as value, the purist would like to know that its 100% correct on its location. As Insperation Gem Silica is still considered one of the best every collected. But the "new insperation mine" in Peru produces pretty nice Gem silica and chrysocolla silicate. However that only been in the last 10+years that i know of.
The value will still vary greatly on several factors, Size, clarity, vein, nugget, faded blue, solid blue, does it have malachite pocketed into it, or other minerals?.
Druzy can be a hit and miss when it comes to a lapidary value. I cant really comment on the specimen value of such. but would except to see, depending on size and condition of the crystals. $10-$30 each.
Prices can vary from $20 per carat, to $100 per pound on true gem silica rough from the Original AZ Inpersation mine. Grading is key to its value.
From Shain - November 17, 2007 at 18:21:43