Garnet

             Garnet is not a single gem but a family of gemstones.  Here I will discuss the common members of that family and a few that are uncommon.  Most people think of an orange-red stone when you say garnet but this gem is available in any color but blue.  It is the traditional birthstone of January.

 

Almandine

            Almandine (also called almandite) is that common orange-red colored garnet.  This is the most common type of garnet and is found all over the world.  It is the same stone used in garnet sand paper.  It is cheap and plentiful, however large stones aren’t commonly cut because they become to dark to show color.


 Rhodolite

            Here is one of the real gems of the garnet family.  It ranges in color from pink to reddish-purple, the color of red wine.  Rhodolite is usually brighter than Almandine, especially in larger gems, and often much brighter in incandescent light rather than fluorescent light.  Stones to 10 carats are easy to get with stones sometimes available to about 100cts.  The gem mines in Africa that have grown explosively for the past two decades are responsible for much of the rhodolite on the market.  Rhodolite forms from a mix of almandine and pyrope.

 

Pyrope

            A personal favorite of mine is pyrope garnet, also called ant-hill garnet.  Unfortunately much of the pyrope on the market is very dark and doesn’t do this stone justice.  The finest pyrope is a fiery bright red, the name is from the Greek pyropos, meaning “fiery-eyed”.  Most available stones are under two carats.

            The rough (uncut) stones come from Africa and, happily, right here in America.  The name ant-hill garnet comes from how the stones are found in the southwest of this country.  Ant-hills in the rocky areas of Arizona and New Mexico are very large and made of pebbles.  Some of the pebbles pushed to the surface by the ants are garnets and peridots.  The ants have already done the work of digging up the stones, all we have to do is sift through them looking for gemstones.

This garnet was very popular in the 19th century in Victorian jewelry.  Called Bohemian garnet, it was often faceted as a “rose cut”, faceted on top with a flat bottom.  This cut became popular again a decade or so ago with the stones being set in inexpensive silver jewelry.

 

Spessartite

Spessartite (also called spessartine) is a yellow to orange colored garnet.  The availability of this garnet is sometimes limited but stones up to 10 carats can be had.  Spessartite is generally more expensive than the red garnets.  Well cut spessartites are bright and lively and usually a bit more colorful than citrine.

 

Grossular

            There are two types of grossular garnet.  The green colored variety is Tsavorite, the honey yellow colored stone is called Hessonite. 

            Tsavorite is named for the Tsavo area in Africa where it was found.  Tiffany & Co. introduced this stone to the US in 1974 making this a recent discovery in the gemstone world.  It is only found in East Africa and reportedly in Pakistan.  Stones over a carat in size are rare.  The color of this garnet ranges from light yellow-green to a bright dark green.

            Hessonite is a yellow or orange form of grossular garnet.  This garnet does not have much of a following in the jewelry field, and it’s unfortunate.  The price is generally cheap.  Most stones are clear, but viewed under magnification inclusions that twist and flow through the stone can be seen.

 

Demantoid

            The rarest of the garnets, this green andradite garnet is rarely seen on the market.  Demantoid is Dutch for “diamond-like”, demantoid’s dispersion is actually higher than diamond.  This means that flashes of color reflected through the stone are impressive, especially in lighter stones.  Under a scope and sometimes with the naked eye “horsetail” inclusions can be seen in some stones, these are a giveaway that the stone is demantoid.  Tiffany & Co. bought all of this gem they could get their hands on in 1868.  Demantoid adorned Victorian jewelry from the late 1800’s and early 1900’s.  Russia was the traditional source for this stone it is now also found in Africa.  Demantoid over two carats was extremely rare.

 

Malaya

            This garnet appeared on the market in the 1960’s, it is a mix of pyrope and spessartite, sometimes with almandine and grossular mixed in for good measure.  Malaya garnet has become fairly popular though it didn’t start out that way.  When it was first discovered the African miners were looking for Rhodolite, which was extremely popular with the Japanese.  When the Japanese saw the yellow-orange stone they wanted nothing to do with it.  This earned the stone the nickname malaya, a KiSwahili word meaning “out of the family”, “outcast” or “prostitute”.  The stone was worthless and the name reflected that.

            Then some Germans and Americans saw the stone.  It became a collector’s stone first then gained popularity in the jewelry market.  Typically available to 10 carats it is one of the more expensive garnets.  Some malayas also show a color change from fluorescent to incandescent light.  Most color change is from orange or yellow changing to purple.

 

            Garnets are fairly stable.  Sudden changes in temperature will fracture them but this is nothing for the consumer to worry about.  Garnet will scratch, the cheaper ones can be replaced while the more valuable ones can be polished.  Chemical cleaners and ultrasonics are safe to use on garnets (unless they are heavily included), steam cleaners should not be used.

 

Other Garnets

            Sometimes a different garnet hits the market, these are usually just an odd color or occurrence of one of the above listed garnets.  That doesn’t mean they aren’t worth putting in jewelry.  A recent example was “Meralani Mint Garnet”, a mint green garnet from Africa.  I don’t know what type of garnet this was, I suspect it was green grossular, but it was a beautiful light green color and I wouldn’t have hesitated to set it in jewelry.
   
           Star garnets are also occasionally available.  The stones are very dark and usually show a four point star.  Most stars are faint and don't often get used in jewelry.

            There are synthetic garnets but they are rarely seen in the jewelry world.  GGG(gadolinium gallium garnet) and YAG(yttrium aluminum garnet) are the two most important.  Once they were used to simulate diamond but were supplanted by CZ.  They are now used in lasers.