A small round, but a brilliant idea.

If you have been following my posts here you probably realized that the availability of tourmaline and its affordability have pushed me to cut practically everything in tourmaline that I have. Years ago I purchased a significant lot of “mine run” tourmaline from Afghanistan for reasons that have long since disappeared.  Even the dealer said that I would not be happy with such small rough, but that was only part of it.  Most of it was fish gravel, but I cut small gems for a year without more investment.

One of the types of rough crystals of tourmaline that I shied away from was thin and with semi-closed ends.  The rough was so small that if I made the crystal thinner, so I had the depth to cut an emerald cut, there would be nothing left and to cut a round with a large difference in tone level, seen face up, due to the dichroic nature of the rough seemed unbalanced.  There was also no way that I could cut a practical round with the dark c axis (principle axis) perpendicular to the table.

So a good part of the small percentage of the lot that was facetable has sat uncut for years.  Now the c axis can have a nice color and it would certainly dominate any stone that was cut from the rough.  And cutting a small stone does not take a great deal of effort, so why not try cutting the “impossible” crystal.  After suffering the usual problems with handling such a small piece of rough and using alumina to make my meets, I was pleased with the round I produced.  (I made a round because it is the thinnest practical faceting cut.) The rounds 4 mm diameter had opened up the semi-closed c axis to a nice darker blue and the a/b axis was flashy.  I can still notice the band of lighter more reflective facets in medium to lower light conditions, but in full sunlight, the whole stone flashes a medium rich blue color without noticeable dichroism.

(This whole story is similar to an effort I posted about with a much bigger round that was included, while my little piece was flawless.  Being flawless and making the orientation of flaws, a critical step in getting  decent gemstone out of included rough, unnecessary,  a long with decent color, were the only reasons the rough was even worth trying to cut.)

I am still looking forward to a new lot of rough from Africa any day, but my little stone did confirm my growing confidence in handling semi-closed, yet colorful tourmaline, without cutting an emerald cut with steep ends.

 

Bruce

About Bruce Fry

I was born in Summit, NJ in 1947 and graduated from Summit High School in 1966. I graduated from the Colorado School of Mines in 1970 and after spending another year in graduate school, I left to see the world of Brazil. After spending some more time discovering myself, I ended up working for the Commonwealth of Pennsylvania for 32 years as an Air Quality Engineer in the Department of Environmental Protection. I retired in 2007 and took up faceting gemstones again after a long hiatus that reached back to my twenties. I had started cutting cabochons when I was 13 and bought my first faceting machine when I was 15, but ran out of money and time until I retired. My great love in gemology is tourmaline and the collection presented here represents my effort to get as much beauty and variety in the colors of tourmaline as I can. I was particularly lucky in being able to get unheated cuprian tourmaline before copper was discovered in gem grade tourmaline from Mozambique.
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