Almandine: description, properties and photo

The color is within the shades of red, purple, sometimes brown and yellowish. Color is associated with the presence of iron and manganese. High transparency crystals are faceted. If the samples contain inclusions and cracks – they are used for making cabochons.

In faceted form almandines are stones of saturated violet-red color, often dark. Low grades are perceived as almost black, translucent or transparent, sometimes containing inclusions. The size is usually up to 5 carats. Stones larger than 15 carats are considered unique. How to choose a gem almandine can be found in the guide.

They are mined in only a few places on the planet if we talk about gem quality, despite the fact that the mineral itself is quite common. These are Brazil, some countries of Africa, Sri Lanka, China, and the USA. There is almandine also in Russia, for example, on the Kola peninsula.

Species containing almandine can be considered as decorative ornamental material. It’s interesting that sometimes the effect of asterism is observed in almandine: in large stones with cabochon form, with a point source of light, a 4 or 6-ray star is observed.

Almandine is a member of the isomorphic series of pyrope-spessartine, that is, it refers to pyralspite garnets by chemical composition. According to studies, the mineral is characterized by impurities Fe3 +, Ca2 +, Mn2 +.

Read more about the classification of garnet minerals here.

In its description almandine is also similar to another red garnets – pyrope and rhodolite. The characteristics of these varieties are very close. First of all, there are differences in chemical composition and density, as well as in optical properties: refractive index and dispersion.

DEPOSITS

Almandine from all varieties of garnet is the most common mineral. As for gem quality, there are few deposits of almandine. Main of them are: Brazil, Austria, China, Sri Lanka, Czech Republic. Also it’s found in Russia. In Ceylon, a gem is mined during the development of placers in Rantapura and near Kandy. Also, a small amount of gem-quality almandine enters the market from African countries: Tanzania (Umba river valley, Kalalani, Lindi deposits), Zimbabwe (Mtoko region), Madagascar. There is a mineral in India, the main deposits are located in Rajasthan, near Jaipur. The origin of the find does not affect the price of almandine.

Interesting facts

• Star garnet is the emblem of the state of Idaho (USA), since the state has the Emerald Creek almandine deposit.
• The largest almandine crystals found is about a meter in length and weighs about a ton. The find was made at the Norwegian Sunfjord deposit. The stone is opaque.
• Almandine was mined from the beginning of the 18th century by the swedes in Russia, in the Ladoga area. They thought it’s a ruby.

Photo

In the photo: red cushion almandine

On the photo: purple garnet

On the photo: large samples of gem almandine in wide color range