Dear friends, I have bought this green tourmaline from Namibia its about 1 carat, well cut in stepped octagon. The color is intense green, with a hint of yellow. It does not turn red under Chelsea filter, thus no chrome is in this stone. I wonder whether such a bright green is due to iron. I know, in fact, that green tourmalines are often colored by iron, but this one is particularly vivid. here some pics
Thank you for all the replies
Last edited by Luca on Fri Jul 14, 2017 3:09 am, edited 1 time in total.
Post subject: Re: Green Tourmaline... no chrome in it, but really brigh
Posted: Thu Jul 13, 2017 1:40 pm
Gemology Online Veteran
Joined: Mon Jun 16, 2014 1:10 pm Posts: 850
Like it very much! Great color...
Found this bright 2,20 ct in St Marie aux Mines.
Sold as a "Merelani" Diopside - the dichroism was to strong and I liked it very much so I took it. With a little hope that it could be a bright green kornerupine too. At the moment they offer some.
So "only" tourmaline - orign unknown - maybe Mozambique ( dealer is specialized in Tanzania gems ) or another african source.
The stone in the original post looks nice but also typical of tourmaline? Maybe it's just my monitor but I don't see anything that makes me think it wouldn't be iron colored, it's just a nice example.
@Barbra thank you for the suggested reading It is really interesting!!!
@Marlow I really like your tourmaline with this nice mint color... I think this particolar hue is rare in a tourmaline.
@Stephen Maybe my tourmaline is colored by iron. However, it seems to me different from other tourmalines I have seen before. So, I supposed that this bright green might be due to a different element. I have read that some green tourmalines (with no red reaction at the Chelsea filter) are colored by vanadium.
Ive posted this pic before because this is chrome tourmaline, african origin & is not readily easy to come by even on the webs, it will change to a reddish color under a chelsea filter & will also change under incandescent light, the chrome content is so high in these stones-
Post subject: Re: Green Tourmaline... no chrome in it, but really bright
Posted: Tue Jul 18, 2017 2:53 pm
Valued Contributor
Joined: Tue Apr 05, 2016 4:08 am Posts: 188
If i may please add-maybe not beautiful, but unique for what they are, nature adds true gems to the menu & variety to see-Ive seen some unique gems in the last few months that were not seen before or were not known of, so to speak-
Post subject: Re: Green Tourmaline... no chrome in it, but really bright
Posted: Tue Jul 18, 2017 4:52 pm
Gold Member
Joined: Fri Oct 19, 2007 5:04 pm Posts: 1642 Location: Walnut Creek, CA
I have one of those large UE chrome tourmalines as well. It's one of my favorite stones, I admit, but from an aesthetic point of view is so dark that under "normal" illumination is almost black.
Only with strong illumination I get bright green and red sparkle. Really beautiful, but if I were to choose a stone to wear, that's just too dark. I'm always tempted to recut it, but I'm sure it won't improve it much, if at all, so I have to live with it...
Post subject: Re: Green Tourmaline... no chrome in it, but really bright
Posted: Tue Jul 18, 2017 11:36 pm
Gemology Online Veteran
Joined: Mon Jun 16, 2014 1:10 pm Posts: 850
Fortunately my stones is not to dark and custom cut ( Coast to Coast ).
A friend of mine, Uli Zeisberg, bought nice CC garnet rough with a visible usambara effect - first time I could see it in garnet. Greyish green bodycolor in daylight but the thicker part in the middle was greyish pink. Can't wait to see the cut stone.
Thank you all for the replies, I definitely agree with Barbra that one specific chromophore (Cr, Vn, Cu) doesn't necessarily confer beauty to a stone. However, it seems to me that the trade market does take this aspect in great consideration. In particular, in my old edition (2015) of the Gem Guide, green tourmaline under 1 ct is valued 25-40 dollars for the fine quality and 40-60 dollars for the extrafine quality. BTW, I have paid my tourmaline more than 60 dollars per carat (no matter since I liked the color). On the other side, in the Guide chrome tourmaline is valued much more (125-250 dollars per carat for the extrafine quality). Thus, it seems that the presence or the absence of a specific chromophore is more important than beauty to estimate the value of a gem? Why? thank you
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