Rubies are considered to be one of the four precious colored gemstones
that have been known since antiquity. They typically range from
blood-red to pink in color.
The blood red ones are the most valuable and the pink ones are
sometimes called pink sapphires. There is no firmly established
guideline as to when the name change occurs.
Rubies are among the hardest of gemstones with a MOH rating of 9 (the
hardest gemstones, diamonds are a 10--glass is a 5)
Color, cut and carat weight are the prime determiners of price. You
will notice in this set that the rubies vary in color.
Since antiquity, most rubies have come from the Mogok Valley in the
area formerly called Burma (now Myanmar)
All natural rubies have imperfections including color impurities and
rutile needles called "silk".
Almost all of the rubies currently used in jewelry are either man made
or the natural ones are heat treated.
If you see a large ruby in a piece of jewelry and it does not show
imperfections under magnification, you can be pretty well assured that
it is manmade.
These demi spoons are from either Burma or Thailand. As you can see the
colors of the rubies differ, although part of the difference is the
The back is only marked 'ss' which I am assuming means sterling silver,
but that is definitely an unconventional marking. I haven't acid tested
The elephant on the right is nice. These spoons probably date before
1900 and I don't think they have been heat treated (although the
process has been available for hundreds of years).
Colored gemstones such as the ruby are heated in computer controlled
ovens to just below their melting point. This allows the aluminum oxide
in the stone to change its molecular shape and as it cools it creates a
new crystal structure.
The chromium in rubies combine with different atoms and creates a
better red color. Many different gemstones are routinely heat treated
which means that our gemstones are significantly prettier than those of
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