Garnets are a set of closely related minerals that form a group, resulting in gemstones in almost every color. Red garnet is one of the most common and widespread of gems, found in metamorphic rocks (which are rocks altered by heat and pressure) on every continent. But not all garnets are as abundant as the red ones. A green garnet, tsavorite, also occurs in metamorphic rocks, but it’s rarer because it needs unusual rock chemistries and special conditions to form. Demantoid is a rare and famous green garnet, spessartine (also called spessarite) is an orange garnet, and rhodolite is a beautiful purple-red garnet. Garnets can even exhibit the color-change phenomenon similar to the rare gemstone alexandrite.
Legend & Lore
Thousands of years ago, red garnet necklaces adorned the necks of Egypt’s pharaohs, and were entombed with their mummified corpses as prized possessions for the afterlife. In ancient Rome, signet rings with carved garnets were used to stamp the wax that secured important documents. Centuries later, in Roman scholar Pliny’s time (23 to 79 AD), red garnets were among the most widely traded gems. In the Middle Ages (about 475 to 1450 AD), red garnet was favored by clergy and nobility.
Pyrope and almandine range in color from purple to orangy red. Spessartine is found in a variety of orange colors, while andradite comes in yellow and yellowish green. Grossular has perhaps the widest color range of any garnet species, from colorless through yellow to reddish orange and orangy red, to a strong, vibrant green. Gemologists and colored stone dealers further subdivide some garnet species into varieties depending on color. For example, demantoid is a brilliant green variety of andradite that’s highly prized by collectors. Both tsavorite and hessonite are varieties of grossular. Tsavorites are green, while hessonite ranges from orange and orangy red to brownish red. Rhodolite is a purplish red variety.
Warm soapy water is always safe for cleaning garnets. The ultrasonic cleaner is usually safe except for stones that have fractures. Steam cleaning is not recommended.
This information was excerpted from GIA's Gem Encyclopedia with permission from GIA.