Tuesday, February 3, 2009


Mexican alexandrite


Q: Can you tell me something about this beautiful ring? I thought it was alexandrite but was told it is corundum and was made around 1880-1910. It is in a rose gold setting marked 14kt, 585, 111 and also has a tiny boat mark. It is fuchsia under indoor lights and changes to blue outside.

A: Corundum is sometimes called "Mexican alexandrite." It is a gem mineral made in the lab by flame fusion, a process developed by Auguste Victor Louis Verneuil in 1893. The number "585" was used in Europe and indicates that the piece is 585 parts gold to 1000 parts, approximately the equivalent of 14kt gold (583 parts gold). The style of your ring suggests that it was made in a Scandinavian country in the 1950s. It is too modern to be a 19th-century piece. Mexican alexandrite rings set in gold sell in Mexico today for about $150.


LindaJ said...

Corundum is more commonly known as sapphire, not Mexican Alexandrite. What that stone appears to be is a natural pink sapphire and as such is worth somewhat more than a lab created made up gem.

waffle said...

Actually Corundum is the mineral that makes up the group of gem stones called Sapphire ( the Red variety is called Ruby)
I believe the confusion arrises with the synthetic varieties of Corundum one of which is a color change variety often called synthetic or lab Alexandrite.

Ellen Faller said...

Naturally occurring corundum (including ruby and sapphire) is NOT called "mexican alexandrite" by anyone! Please note that *corundum* is a naturally occurring mineral, and it its finer, gem quality varieties is known as ruby or sapphire depending on the color. Alexandrite is a gem variety of the mineral chrysoberyl,and it has a natural color change as one of its properties.
*Synthetic corundum* has been made for decades, as mentioned. One form of the *man-made material* has the color-change property and has been used as an imitation of alexandrite. Sellers will use the "mexican" prefix to try to enhance the value of such a stone with a buyer, hoping to snag them with the less than accurate alexandrite term. The material is neither mexican, nor alexandrite, but is most likely the synthetic product with corundum's composition.
If it is a pretty stone, just enjoy it!

Coin-Op Pop said...

Corundum is commonly called sapphire (red corundum is called ruby). The stone you are describing is called color-change sapphire. I don't know if color-change sapphire occurs naturally anywhere in the world, but I wouldn't assume any gemstone was synthetic without examining it with a microscope.

Anonymous said...

The ring looks almost identical to a ring I bought in Israel in the
70's which was made of rose gold and had an alexandrite stone. The use of Rose gold in jewelry was very common in Israel in the 70's.

Anonymous said...

This "stone" appears to be Fabulite to me, though it is not a very good photo. You should take it to a local gemologist and have it tested. It most definately appears to man-made though.

Laurel S.

Carol said...

As others have said corundum is the technical name for a group of minerals. Natural corundum occurs in an incredible number of colors. Those seen in jewelry most commonly are sapphire (blue), ruby (red), and white sapphire (clear).

Synthetic sapphires have been around since the 1800s and, being inexpensive, have been used extensively in jewelry. Many of the tiny blue accent stones in 1920s filigree rings and bracelets, for example, are synthetic sapphire.

Synthetic color change sapphires (most with a color change from teal blue to hot pink) are dramatic in appearance and have been popular in jewelry since the 1920s or 1930s. Many, many people are "sure" that these stones (which are typically very large) are alexandrites.

Natural alexandrites are expensive and typically do not have as dramatic a color change as synthetic color change sapphires. A sure way to tell the difference without any tests is size. Alexandrites simply don't occur in large sizes. A 1 ct natural alexandrite would be considered quite large (with a wholesale pricetag of mid-hundreds of dollars at least). The synthetic color change sapphires used in jewelry are usually at least 5 ct.

Cluster Earrings said...

Cocktail rings are most famous rings as these are rings have a centered diamond with many surrounded tiny diamonds, nearly any oversized ladies' ring may be termed "cocktail".