Blue cap round from face up.This is a unique tourmaline in the collection. It has a grayish blue table, that's color goes half way toward the girdle, which is peach. It has a deep pavilion of split horizontal mains. It weighs 1.87 carats.
Blue cap round, more from the side.
I set out to cut a different stone from a different piece of rough this time. Blue capped tourmaline crystals are some of the most beautiful and interesting specimens of tourmaline in the world’s museums. It is another one of the color distributions, like watermelon with its concentric layers of green and white over a pink center that has caught the public fancy. Just as I have found it difficult to actually find a watermelon tourmaline worth faceting, I have, up until this piece, failed to find a blue cap to even try cutting.
When I received this rough crystal, at first, I though I had a strongly dichroic tourmaline. But it soon became obvious that the blue, seen down the c axis, was just a thin layer of dark blue at one end of the crystal (terminus). I know if I wanted to have a nice blue stone face up, I had to put the blue cap in the culet of the stone, but then what fun would that be. A unique piece of rough deserved an exceptional treatment and I decided to grind the table out of the blue cap. This could lead to a number of things. Having difficulty with polishing such an intensely colored table is certainly not out of the question, since “normal” table perpendicular to the principle axis (c) can be be difficult. The blue cap might be just plain unstable and there goes the stone. Such is life, it was not a big investment. And finally, the blue was so intense that I might not see the ink color of the main part of the rough in the finished gemstone.
I always cut the pavilion of my gemstones first, to insure that I have established a gemstone with the correct pavilion angles that are critical to the beauty of the stone. Adjusting the crown angles is far less critical. Now cutting the pavilion is usually not a problem, but with the blue cap, if I ground off too much pink or too little pink, the thin blue layer would not be easy to incorporate into the table. To complicate the matter, I decided to make a deep pavilion by using horizontally spit mains. Perhaps I would get a little more color out of the rather pale pink body of the crystal in the finished gemstone.
So off we go into the wild blue yonder. As I cut, I can see that the really intense surface of the old terminus is very thin and that the blue does penetrate the body of the crystal to a degree. ( a fraction of a mm) The cutting and polishing of the pastel pink pavilion goes well and no one makes a break for it. As I transfer the stone, I am thinking that the real fun might begin.
The intense blue band is slowly ground off because of something I did not foresee. It had a bad case, of the lack of transparency, that I have seen in other blues. Now, will I grind it all away and accept a rather pale average peach from this rough, or? No, I can see a much less intense gradient of blue that I can retain as the table. I also came to realize that the blue will extend less than half way down the thickness of the crown, so some peach will shine threw, face up. It is time to stop, I can see threw the table, the blue gradient is in place and the peach awaits me. I will try and post a couple of pictures, one from face up and the other from the side to give you a better visual.
Cutting the breaks confirm my blue table configuration and the girdle I expected to see around it, but how balance the colors will be is anybody’s guess. The polishing of the table, small as it is, is the last question mark and that goes well. I always say that I have a stone in my grasp, when I finish the table. In other words I am in control and the work is almost done.
While cleaning the stone in alcohol and drying it, I try not to look at the stone. It takes a bit of time for the stone to dry and I don’t want to see this one dead from being wet, for my first impression. Well it is interesting, the blue has turned more gray and it is still limiting the flash under the table. The gray comes down the side of the crown at least halfway to the girdle, but the stone has a bright flashy band of medium toned pink encircling the table area.
I can’t call this one beautiful, but I ended up accomplishing what I set out to do. Make a different stone from a different piece of rough that I doubt my dealer would have even handled except for the extreme shortage of tourmaline rough on the market to day. I rather like it difference and appreciate that it doesn’t roam the trays scaring little tender tourmalines. It weighs 1.87 carats.