[GemWise] Tucson 2009, Wrap-up

Rubies From Winza, Tanzania:

As promised, here is an image of the 4.10 carat cushion shaped ruby
from the new strike at Winza, Tanzania. Ruby from this source
contains iron, though not as much as gems from the now exhausted Thai
deposits. Stones from this source will not fluoresce strongly in
ultraviolet light and thus will not exhibit the supercharged
fluorescence of the very best from Burma. Again, due to iron, the red
may show a slightly orangy secondary hue.

That said, natural unenhanced rubies over three carats are almost
unobtainable. These new Winza beauties will stand toe to toe with
most Burmese at a much more reasonable price.

An Extraordinary Strand of Natural Pearls:

I spotted a magnificent strand of natural pearls from a dealer at
AGTA. What makes this two strand exceptional is its symmetry. When
consideri ng [PictuRe: NatPeaSingle.jpg (image)] natural pearls it
necessary to bracket all that you have come to expect from their
cultured counterparts. The word round, for example, takes on a whole
new meaning when applied to naturals. We have gotten used to the
“perfection” of the ubiquitous Akoya pearls from Japan, perfectly
round, with matching color. Few realize that all this is a result of
processing; the pearls are left in the shell just long enough to
deposit a thin coat of nacre, so thin that GIA had to redefine it’s
definition of “thick” coating from 0.50 to 0.25mm. The pearls are
then bleached white to remove spots, then further bleached for
uniformity of color, then dyed pink.

The World Of Fantasy:

In the world of natural pearls, perfect symmetry, combined with
matching color, resides in the realm of fantasy. The strand pictured
right is natural, the pearls graduate from 4.31-9.50mm, each is
perfectly round and well matched in color and luster. Compare these
two with the Baroda Pearls (pictured left). Readers will recall that
the Baroda strand sold at a world record price. A cursory look
reveals that these magnificent gems are not really round—yet they
achieved a record of $7.1 million at auction.

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