AZGem Gems
May, 2008

gem stone and jewelry newslettergem stone and jewelry newsletter

The World's Most Useful
Gem & Jewelry Monthly Newsletter

Written by Carolyn Doyle for customers of
The Dorado Company
and other visitors to the website who subscribe.


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Usable Gems... and a little opinion.


Spinel Gems Are Real


spinel gems are real


Spinel gems are beautiful, colorful, durable... and somewhat rare

"Spinel gemstones are all fake. The lady at (discount superstore) told me so!"

After reading last month's newsletter attesting to the fact that zircons are real gems, I received this response from a reader



My response to her is... "Real spinel gems are  produced by Mother Nature, just as gem zircons are. Man does  produce a synthetic version of spinel in the laboratory for use in class rings and low cost jewelry, so the lady at the store is probably accurate in describing her jewelry."

Synthetic spinel is readily identified with a microscope or by measuring the refractive index or specific gravity with gem instruments. Also, the chemical formula is a little different than natural spinel.

Spinel is actually a mineral group called magnesium aluminum oxides. The spinel family of gems all have similar chemistry and crystal structure.


spinel gems are colorful

spinel gems are real


Red spinel is historically the most prized color. Many red spinels were originally identified as rubies. The Black Prince Ruby in the British crown is a great example.

Spinel gems naturally occur in many other colors as well, including pink,blue spinel gems are real orange, green, blue, purple, violet, lavender, white (colorless), and black.

Experts are divided on the question of whether natural spinel occurs in yellow. I've seen yellowish-green stones, but never a true yellow.

Pure spinel is colorless. Colors occur when nature allows chromium, cobalt, iron, zinc, manganese, and/or nickel to substitute for a little of the magnesium or aluminum in the crystal lattice.

Red spinel gems are colored by chromium, just as rubies are.

Natural spinel gems are closely related to sapphire and ruby. (corundum) in chemistry. Corundum is aluminum oxide (no magnesium).

Here is a table showing the similarities of spinel and corundum.



Ruby and Sapphire
 Chemistry  MgAl2O4  Al2O3
 Hardness  8  9
 Refractive Index  1.718  1.762 – 1.770
 Crystal Structure  Cubic  Hexagonal
 Specific Gravity  3.63  4.00



Spinel gems are more rare than sapphires and rubies, but curiously, about one third the price. In my opinion, they are just as beautiful. I consider all that to be good news.

Because these to gems are so similar, it is not surprising that they occur together in metamorphosed impure limestone (marble), and in the gem gravels that result from the decomposition of the marble.

It is thought that the spinels crystallize first, using up the available magnesium. Gems that crystallize after that are corundum because of the lack of magnesium.



Spinel is a name with disputed origin. Some say the word comes from the Latin word "spina" (thorn), a reference to the common crystal shape. Others theorize the name is from the Greek word "spinther" (spark), a reference to color.

Spinel ruby is an outmoded name applied to this gem. Other old names include balas ruby. This a reference to the ancient mining location of Badakhshan, a region comprising parts of northeastern Afghanistan and southeastern Tajikistan. Spinel was mined there in ancient times. about the year 750 AD, and probably earlier. 

Spinel gems were recognized as a distinct species in 1587 in Burma (now Myanmar), but was not recognized in other parts of the world for another several hundred years.

The earliest known use of spinel for adornment was about 100 BC in a Buddhist tomb in Afghanistan.

Spinel gems are now mined in Tanzania, Madagascar, Sri Lanka, Vietnam, Burma, Afghanistan, and neighboring regions of Central Asia. There are other, less commercially important deposits in additional locations.


spinel gems is a keyword search phrase that return a number of internet listings and ads... but probably none with prices as low as mine.




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Gem Industry News...


Auction Sets New High For A Rolex Datona


A record price for a Rolex Datona watch was set at a recent “Important Watches” sale at Sotheby’s in New York City.

The Rolex stainless steel Oyster Cosmograph Daytona sold for $505,000 to a private bidder (price included buyer's premium). It was a new record for a Rolex Daytona and the second-highest price achieved in auction for any Rolex watch.

A number of Patek Philippe timepieces also sold at high prices. A gold automatic minute repeater with hinged case went, for $301,000; a large gold automatic perpetual calendar with Doré dial and moon-phases, for $400,000 and a platinum rectangular tourbillon with 10-day power reserve, for $265,000.

“The results demonstrate the strength of the market for modern watches, particularly Patek Philippe, as well as for unusual Rolex sports model watches,” said Aaron Rich, head of the Watches Department in New York. “We saw excellent global participation with bidders from Europe, Asia and America.”


The Las Vegas Gem Shows Are Here


The Las Vegas gem shows will begin at the end of May. If you're going, let us know. We may be able to get together for coffee...


gemstone news


Jewelry Dealers


wholesale jewelryMother's Day and graduation season are right around the corner... plus, anniversaries and birthdays are always coming up.

All are good reasons for your customers and their friends to buy jewelry.


Are you rewarding your customers with discounts or freebies when they send you a new customer? 


Keep the  Make An Offer program in mind. You can always pick up a few good deals there. 


gemstone news


Jewelry Dealers Program

Do you enjoy jewelry and gems?sapphire ring

Do you enjoy talking with friends and co-workers?

Could you use an extra income source?

Take a look at our great Jewelry Dealers Program.



Carolyn Doyle

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