Big Oval Blue Purple that did not get away.#943

Large Blue/Purple include Oval (Laurellite) This 27.13 carat oval has a significant amount of veils and inclusions, but it is still flashy and very rare in its size, color and color changing properties. (Laurellite)

 

Buying tourmaline rough over the inter net or even in person can be an adventure.   This large oval, at 27.13, carats is one of the larger gemstones in the collection.  It was cut from a piece of rough that was over 100 carats, that a number of veils and inclusions that are still retained in the gemstone.   When I first saw a picture of the rough on the interne, I thought that I could carefully slice and dice a number of smaller fairly clean stones of it with a decent level of tone.  When I received the rough, I saw that there was only one relatively small area that would make a clean gemstone and that the tone level was great for a big stone, but not smaller ones.  Now remembering a beautiful sapphire I had seen in a traveling show at the museum, (it had a large swirling feather threw the heart of a LARGE very beautifully colored gem and it still was treasured) I decided to cut the biggest reasonably pure stone I could.   It was an effort and the table is not as perfect as I would like, but when you polish large included stones you have to accept their limitations.

Another property of the blue/purple tourmaline I checked out immediately upon recite was how its color responded to different white lights.  It changes from violet in natural light to blue in incandescent, just like the emerald cut I sent to the GIA  and found to be a strong color changer.  So I consider this gemstone to be a “Laurellite”, which is a name that I gave to the new variety of tourmaline that is copper bearing, from Mozambique and that demonstrate a reverse Alexandrite color change as described in the sentence above.

Now I have to really look at this gemstone for the first time in awhile and judge its overall appearance. None of the imperfections in the gemstone flash when are viewed face up.  Even at reasonable angles the flaws produce a filtering effect rather than flash, except for a small area just off the edge of the table.  The gemstone has a good tone level and flash for an oval.  The quality of its crystal (parts of the gemstone that are not included) is very good.

I think, in the end, I made the right decision with this gemstone in an imperfect world.  It ended up being a attractive, extremely rare  gemstone that between its great size and color changing nature is exceptional.  I feel fortunate to have been able to get the rough that was available in this size/quality for only a short time.  It also helped to have some money from retiring to be able to afford the piece.

One final note.  You must be very careful in selecting the lighting conditions under which  you evaluate color change gemstones, if you want to see the best color change.  Most situations in the everyday world are mixed lighting and you therefor get to see both the blue and violet components of the color changer, at the same time in the gemstone.

 

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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