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BURMA |
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Page under construction. |
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Burma is
generally regarded for the finest rubies, against which
all others are compared. However, the country has numerous
corundum localities that produce everything from ugly specimens only a
geologist could love to the finest of gemstones. It is arguably
host to the most significant and diverse corundum distribution in the
World. |
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Unfortunately, gem ruby crystals are very hard to obtain. Politics
(a.k.a. the embargo) and the fact that gem crystals are often sold
directly to cutters contribute to this. Now (early 2012), it
appears the first problem may be thawing. |
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PAINITE WITH RUBIES |
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The mineral painite was considered one of
the Worlds rarest minerals, but late in 2005 new discoveries near
the Mogok Stone Tract (Ohngaing and Wetloo Mines, near Kyauk Pya Tart)
raised the number of known specimens from a couple of dozen to a couple
of thousand, counting all the bird seed fragments. Needless to say,
this was big news to dealers (most notably, Bill Larson), and collectors
of this "Holy Grail" of species eagerly paid exacerbated prices for
even dinky little specimens. Only a few specimens weighed more than
one ounce, and initially these commanded prices in the thousands of dollars. |
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For further reading, I
recommend two superb articles about painite by George Rossman (Rossman
et al. [1])
and Vincent Pardieu (Pardieu et al. [1]). Together, they give a comprehensive
overview of everything from history and geography to gemology and
chemistry.
[Links to be provided - all articles
referenced Google up easily!] |
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What
interested this corundum collector was that a small fraction of these
new specimens had druzes or crystals of ruby
attached. A superb example with gem ruby crystals both
attached and included, acquired from Siggi
Ellenberger in 2006, appears on the left. In another
specimen (right image,; donated to our collection by Bill
Larson), painite seemed to have altered to ruby! Since the ideal chemical formula for painite is CaZrBAl9O18 and that of
corundum is Al2O3, the
association and the alteration were not great surprises.
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Painite with ruby |
Ruby pseudomorph after painite |
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This matrix specimen (left) is a
superb study piece, obtained from Siggi Ellenberger. |
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Spectrographic analysis of painite
specimens and geological site work have led to some understanding of their genesis
and the environments where they formed. Skarns (in this
case, contacts between calcite and leucogranite) proved conducive to
formation of painite; and where these occurred in ruby localities
(Wet Loo and Namya , both in Burma), the
association was found. The Wetloo Mine, near Kyauk Pya
Tart, is perhaps the most notorious (see Rossman [1], Pardieu [1]).
Thus, it appears rubies can form in skarns - an interesting new
observation (George Harlow: Harlow et al. [1], and pers.
conv.)! |
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Painites,
and a sapphire... |
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A colleague who frequently goes
to Burma found some very large (relatively speaking) specimens, which he
purchased from the monks at the Kyauk Pya Thart Monastery
In all, there were well over 100 specimens (left image shows some of
them). Among them were a doubly terminated painite crystal (no
rubies) weighing more than 500 carats and a huge corundum after
painite pseudomorph weighing nearly
900 carats (right images). |
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Painite
crystal |
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Corundum
after painite |
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After selling a
few for the owner, we struck a deal for the rest of them. I
have been asked if some would be sold, but for now we are keeping
the collection intact. My two favorites are below. |
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The one on the left is
3 inches long, and it weighs about 180 grams (900 carats). The other
(right) is a cluster of lustrous, ruby encrusted painite
crystals on a base of massive ruby corundum. It measures about 3-3/4" by 3-1/4" by 2",
and it weighs about 456 grams (2,280 carats). Even if
the painite is ignored, these are lovely ruby cabinet specimens!
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In the past several
months, very little painite has been found, and there are geological
reasons to believe the deposit near Kyauk Pya Thart has been
"mined out". It will be interesting to see whether history
sees these rarities as historically significant or merely as
curiosities. |
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To he right is a superb Burmese octahedral corundum after spinel
pseudomorph from the Ed David collection, obtained through the
efforts of Rob Lavinsky (a nice companion for the Viet Namese
octahedron on the Home page). Contrary to a rumor which may be
circulating, it is not an oo aa bird egg. |
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Ruby druses are rare, but
this one from Spider Mountain, Mogok Stone Tract, Burma
is superb (ex coll. Bill Larson). |
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Gem ruby crystal from the
Dat Taw Mine, Mogok Stone Tract, Burma, showing wavy
lines which often characterize Burmese corundum. |
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Gem lilac crystal from the
Dattaw Mine, Mogok, Burma. |
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Unique pyramidal point of
gem corundum resembling smoky quartz in body color, covered with
a white druse of as yet undetermined composition (probably
corundum or spinel); from Baw Mar, Burma. |
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Gem complex, multiply
terminated and multicolored crystal from the Dat Taw Mine,
Mogok, Burma. |
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Mong Hsu terminated ruby crystal with a blue
sapphire core. |
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