Garnet is the birthstone for January and the gem for the 2nd anniversary. Some believe the true value of a garnet birthstone is, its power to bring the wearer good health, wealth, and happiness. Garnets belong to a group of over 20 closely-related minerals with the same crystal structure but slightly different chemical compositions. It includes five garnet species that are commercially important as gems. Those five are pyrope,almandine, spessartine, grossular, and andradite. A sixth, uvarovite green garnet.
1) Pyrope and almandine: Most red garnets on the market are mixtures of pyrope and almandine. Pyrope is almost always red to very slightly brownish-red and almandine is typically red to brownish-red or purple-red. Only differ in their chemistry, silicon, oxygen, and aluminum are found in both, pyrope contains magnesium and almandine contains iron. Rhodolite garnet is a mixture of pyrope and almandine. Sources: Rhodolite:-Umba river, Tanzania, Madagascar, Brazil, Sri Lanka, and Zimbabwe. Red garnet:- Mozambique, Thailand, Madagascar, Brazil, and Arizona, USA.
2) Spessartine: Spessartine garnet is a nesosilicate, manganese, and aluminum garnet species, with a vibrant orange color component. It's named after the Spessart district of Bavaria, Germany where it was first discovered. Mandarin Garnet, in 1990, vibrant orange spessartine from new sources in Namibia and Nigeria as " Mandarin" garnet a reference to the gems. Sources: Namibia, Nigeria, Madagascar, India, and Sri Lanka.
3) Pyrope-spessartine: Color change garnet and malaya garnet are mixtures of pyrope and spessartine. Color change garnet, which shows a distinct color change from green to bluish-green in the day (or fluorescent) light and red to reddish-purple in incandescent light, contains vanadium. Malaya garnet, Malaya comes from a Swahili word that means " out of family" or "outcast". Slightly pinkish-orange, reddish-orange garnet. Sources: Tanzania's Umba River Valley, Kenya, and Sri Lanka.
4) Grossular: Grossular garnet is a calcium-aluminum species of garnet. Garnet occurs in a diversity of colors, including tones of orange' yellow, and green, Hessonite and tsavorite are grossular species of garnet. Sources: Kenya, Tanzania, Madagascar, Brazil, India, and Sri Lanka.
5) Andradite: Andradite is a nesosilicate mineral species of the garnet group. There are three varieties have been recognized by gemologists: demantoid, melanite, and topazolite.
Demantoid Garnet: A rare gem with a vivid yellowish-green color variety of andradite and higher dispersion than diamond. It was first discovered by gold and platinum miners in Russia"s the Ural Mountains in the mid-1800s. Russian demantoids are curving, radiating bundles of fibers known as " horsetails" inclusion. Sources: Russia, Namibia, and Pakistan.
Melanite garnet: A opaque black color garnet contains titanium oxide. Sources: Russia and Mali, Africa.
Topazolite garnet: Yellow to yellow-brown or golden brown color garnet. Sources: Mexico, Namibia, and Madagascar.
- Mineral: Garnet Group
- Almandine- Fe3Al2(SiO4)3
- Andradite- Ca3Fe2(SiO4)3
- Grossular- Ca3Al2(SiO4)3
- Pyrope- Mg3Al2(SiO4)3
- Rhodolite- (Mg, Fe)3Al2(SiO4)3
- Spessartine- Mn3Al2(SiO4)3
- Color: All colors
- Refractive index: 1.714-1.888
- Birefringence: None
- Specific gravity: 3.47-4.15
- Mohs hardness: 6.5-7.5 on the Mohs scale.
- Stability: Garnets are stable to light and chemicals. They can be attacked by hydrofluoric acid.
Cleaning: 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.
- Treatment: Garnets might rarely be treated by fracture filling.