Saturday, February 19, 2011

Name that Stone!

This blue stone was sold to a store by a mystery person off the street. Its origins are unknown. I bought the rough and cut this blue agate material out of the host rock to make these two blue cabachons and this necklace. The color of the cabs is a striking bright blue and on one corner along the side (too small to be visible to the camera), is a small 'flower' of what looks like malachite. I got the rough for nine dollars, what a deal! Does anyone have any idea where this material might have originally come from? Since it's blue and looks like agate, I am guessing it's likely to be a high quality gem silica of some kind, probably from an older collecting location.

Update: OK, looks like most people agree this rock is probably gem silica, perhaps from Arizona. It also looks similar to Needles Blue agate, which is also a very nice colored blue stone, but the host rock on my cabs does not look like rhyolite which is often the host rock of Needles blue. Here is a pic of the back of the cabs which shows some host rock that I left behind when I cabbed it.


  1. Hi Eva...this sure looks like Needles Blue Agate. (Needles Gem and Mineral own the rights to the mine.) Do you have any pictures before you cut out of the host rock? You can email me at

  2. Email me and I can send you a pic of the back of the cabs where I left some of the host rock. Needles blue was actually my first guess some time ago, but other people in my club didn't agree. They thought it was similar but no cigar. But since you are from the Needles club, you'd probably be the best judge!

  3. Wow, good peruvian blue opal does look a lot like that, you are right. (I just googled it). However, with that bit of malachite in the corner of the stone, my money is still on gem silica. Interesting to learn more about the peruvian though..