Garnet Family


Mg3Al2(SiO4)3 - Fe3Al2(SiO4)3 - Mn3Al2(SiO4)3
Pyrope - Almandine - Spessartite


Isometric (rhombic, dodecahedron, isoctohedron, and trapezohedron)


red, red-brown, black, green, orange, purple, yellow

Refrac. Index:

1.69 - 1.86


0.022 - 0.057


6.5 - 7.5

Spec. Grav.:

3.6 - 4.2






garnets area solid solution series, and occur in contact metamorphics, serpentines


scapolite, diopside, calcite, wollastonite, kimberlite, tremolite


| Italy | Turkey | Calif.., N.J., N.C., Col., USA | Sri Lanka | Norway | Bohemia |


The name almandine comes from the Anotolian city of Alabanda; the name Andradite comes from the Brazilian mineralogist J.B. d'Andrada; the name Grossular comes from the Greek "grossularia", "meaning gooseberry"; the name Pyrope comes from the Greek "pyropos", meaning "fire-eyed" for its red color; the name Spessartite comes from Spessart mining district in Bavaria; and the name Uvarovite comes from the Russian noble man, Count Sergei Uvarov. The garnets make up two solid solution series; 1) pyrope-almandine-spessarite and 2) uvarovite-grossularite-andradite. The majority of garnet goes into the manufacture of sand-paper.

Gem info:

Almandine is the deep-red iron rich garnet and often cut into ovals. If the stone is deep it may appear too dark and has less value. Much of the older Victorian jewelry used these garnets.

Pyrope is a fiery red garnet, but it too may suffer from being too dark. Large stones are often available but it is not one of the more highly priced gems.

"Rhodolite" is a special variety of the Almandine-Pyrope mix. It is about 1/2 way between the two end members and is a reddish-purple stone usually with good clarity. It is very popular today, and is among the more expensive of the red garnets. It is still not in the price range of good imperial topaz, aquamarine or good tourmalines. It is a second tier stone.

Spessartite is a manganese rich variety that may be orange to orange-brown in color and large stones are usually not available. It is priced above Almandine and Pyrope and about the same level as rhodolite.

Grossular garnets come manly in a yellow color from Sri Lanka. It also comes in a yellow-brown variety with the name "Hessonite" (from the Greek "esson", meaning inferior). Today the most prized member of the garnet family is the green grossular garnet called "Tsavorite" from near the Tsavo National park in Kenya. This green garnet gets it's color from chromium just like emerald. It is sold as an emerald substitute and brings a quality price. Large stones above 3 carats are very uncommon.

Andradite garnet is usually black and of no interest to the gem trade, but one variety called "Demantoid" is a lively green. It is a little on the softside and very brittle so it needs good protection in jewelry. It brings a premium price, but is available only in small stones.

Uvarovite rarely occurs in facetible sizes, but when it does it makes a spectacular stone. If it is emerald green in color it can bring a hefty price. If too dark, it not worth nearly as much.