I'm trying to plan my next earring. I want a cohesive look and I think it looks better when the stones match. I was originally planning just amethyst (dark) and tanzanite but I'm really interested in a labradorite end I found. It would only be next to the tanzanite for now but I want to see them all together just in case. I don't want too many different stones. So, anyone have these near each other and have pics? Opinions? Thanks!
Tanzanite is the trade name for blue zoisite. The only known deposit so far discovered is in the hills outside of Mererani, Tanzania. While a small fraction of the gems mined come out of the ground a natural blue color, most are various shades of brownish, and only develop their color after gentle heating. Unlike sapphires where we heat the rough before cutting, with zoisite you want to cut it first and cut it to be as clean as possible, so that cracks or inclusions do not crack and spread in the heating process.
This particular Tanzanite was one I cut this past year from a large piece of rough that I cut out of a crystal specimen. Rough exports from Tanzania have been limited for quite a few years now in an effort to develop the cutting industry there (alas, that's mostly been a failure, and instead led to even more corruption and truly failed to help the locals, but that's a story for another day). In terms of finding large rough, it's very difficult as the only exports allowed now are rough under two grams. Every now and then an old piece of rough that has been stashed away will turn up, or in the case of this gem, I bought a large old crystal from a collector who had it for decades. For the most part now when I want to cut a larger stone I have to cut one that's already been poorly cut and exported, and then recut it, so it's not often you get to see an unheated piece of this size in the before and after state.
Now, more about the color. Zoisite is trichroic--which means that the three major axes of the crystal all show a different color as the light passes through it. This is caused by the molecular structure of the crystal matrix as it bends the light passing through, and how it interacts with the vanadium ions in the crystal lattice. Typically one axis will show blue, one will show more green and the other a reddish-purple. This can vary a good bit, with hues of orangey-brown common. The cut gems will always show some mix of colors as a result, and often end up brownish from this color mixing--as you can see here. Heating changes the oxidation state of the vanadium ions and great reduces the yellowish-brown components of the color, leaving a more pure blue and purple-blue as the dominant colors.
UPDATE: Video link on the hand in daylight. https://www.youtube.com/watch?v=5zbFLBnzotU
https://preview.redd.it/f77txbonrsz71.jpg?width=1200&format=pjpg&auto=webp&s=a1bd4a52d989
... keep reading on reddit ➡