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Usable Gems... and a little opinion.
Color Change Gems
Color change gems are the subject of this month's newsletter, the
fourth in a series on
optical phenomena gems.
Color change gems do just that... they change color
under different types of light.
This change can be dramatic. For example, a green gem when
viewed in daylight becomes a red gem when viewed under some
artificial light sources, including the common light bulb.
This optical phenomena is also known as the "alexandrite
effect" because it was first observed in alexandrite (the chromium
containing variety of chrysoberyl).
Alexandrite has a
distinguished history: it was discovered in 1830 in Tsarist Russia.
Since the Russian imperial colors were red and green, the gem was named after Tsar
Alexander II on the occasion of his coming of age.
For the next 150 years
alexandrite was certainly the most famous and expensive of the rare gems.
But... in 1987 a new find of
alexandrite was made in Brazil. The Brazilian alexandrite shows a striking and attractive color change from raspberry red to
that time alexandrite has also been found in Sri
Lanka, Magascar, and Zimbabwe. As a result, alexandrite is somewhat more
available and affordable.
Other gem varieties, including
spinel, tourmaline, garnet, and sapphire can exhibit this unusual optical
phenomena... and different color change combinations.
By way of example, here's an
orange-to-pink color change sapphire.
Hope Diamond was once the French Blue
Researchers using computer analysis have concluded that
the Hope Diamond was cut from a larger stone that was once part of
the crown jewels of France.
This French connection had been suspected for the famous
diamond, but the new technical research and analysis shows
just how it would have fit inside the larger French Blue diamond, according to Smithsonian gem curator Jeffrey Post.
The deep blue Hope Diamond is the most important gem in
the Smithsonian National Museum of Natural History's gem collection.
The study helps confirm what has long been suspected... the Hope Diamond
was originally a 115-carat
stone found in India in 1668. That stone was sold to King Louis XIV of France.
The king had it cut into the 69-carat French Blue. The French Blue was among the
many crown jewels that disappeared during
the French Revolution.
Just about twenty years later a
large blue diamond was put up for sale in London.
This stone was purchased by Henry
Philip Hope, hence the name Hope Diamond.
The beautiful gem eventually was bought by jeweler Harry Winston,
who later donated it to the Smithsonian.
Even at its current weight of 45.52
carats the Hope Diamond is the world's largest blue diamond.
Post said existing sketches of the missing French Blue
diamond are quite detailed and allowed preparation of a computer model of that
After using the sketches and analysis to make a computer model of the
French Blue, and modeling the Hope Diamond, researchers "virtually placed the Hope back
inside the French Blue" Post said.
"It turns out it actually fits perfectly in only one way, but at that
orientation, when you saw how it fit, you could see why it was cut the way it
is," Post said.
"They cut the corners off the French Blue, changed slightly the angle of
the bottom facets, and that produced the Hope Diamond," he said.
I hope you noticed our new addition... advertisments.
It's another small source of revenue for
us (gotta keep those gem prices down) and possibly another resource for you.
We're not sure who will be advertising, since we don't control that. I'm
guessing on-line jewelry sales sites... and maybe even other gem dealers.
I hope the ads will be useful to you.
We'll be adding ads to many of our pages
as we remodel and freshen our web site.
The Tucson Shows were great as usual. Attendance
was up this year. And they were buying.
Our cutter from Sri Lanka made several large sales while
we were at his booth to drop off sapphire rough. (He'll take the rough back to
his lapidary factory in Sri Lanka and facet the stones for us.)
We only visited a select few shows, as is our
custom. It's just not possible to work through all of the shows, so we go to the
ones where we have prearranged business... and one or two more.
There were more than forty different shows going on in
various locations scattered around town this year. The number of shows keeps on
Are you making up heart pendants, stud earrings and other
jewelry for Valentine's Day customers? Now is the time! Talk it up, and
make those sales.