Almandine is the most common form of the gemstone Garnet. The term Garnet describes a group name for several closely related minerals that form important gemstones, and Almandine is an individual member mineral of the Garnet group.
Almandine is usually opaque and unfit for gemstones use; though the less common transparent to translucent forms make fine gemstones. In the gem trade, the term Almandine is rarely used on its own. It is either generically called "Garnet", or "Almandine Garnet". Almandine is almost invariably dark in color, and it forms dark red to reddish-brown Garnet gemstones.
Almandine is the hardest form of Garnet, and a pure deep red is its most valuable color. Almandine Garnets are occasionally hollowed in their underside to allow more light to enter a stone, giving a cut gemstone a lighter appearance. If the bottom of an Almandine gemstone is covered by a jewelry setting, the only way to easily determine if it is hollow is by its lighter weight.