Trigonal Gemstones & Minerals

The following is a list of Trigonal gems and minerals listed in our database. Click the pictures to get full data, click the X to remove the gem from the list.

Rubellite Tourmaline

Rubellite Tourmaline: Rubellite is the pink to red variety of Tourmaline, which is a complex borosilicate of aluminum and alkali, with iron, magnesium, and other cations. It is found as fine acicular crystals in rocks, or as large individual crystals grown upon matrix where they may reach a weight of several kilograms. Most form elongated and striated trigonal (three-sided) prisms and these are terminated with trigona (read full)

Schorl Tourmaline

Schorl Tourmaline: Schorl is the black, opaque, sodium iron rich variety of Tourmaline, a complex borosilicate with a trigonal crystal system.
Tourmalines usually occur as long, three-sided prisms, which often have well-terminated ends. Sometimes they are found as parallel or radiating groups of long, thin prisms with striated ridges lining its surface. Its varieties span the widest color ranges in the mineral (read full)

Achroite Tourmaline

Achroite Tourmaline: Colorless Tourmaline, also known as white or Achroite Tourmaline is the name given to the clear or colorless version of Tourmaline. The word achroite is Greek for colorless. If you are into birthstones then Achroite Tourmaline is one of the ones used for October. If you follow the zodiac then it's used to represent Libra. Tourmaline in general is found on every continent and is possibly the (read full)


Amethyst: Amethyst is the most coveted stone in the quartz group, and it is sometimes confused with beryl. It is usually found layered with milky quartz, and its color varies from purple to violet. It is sometimes sold as Ametrine, but this is actually a combined variation of 2 gems; Amethyst and Citrine. Amethyst like Agate Chalcedony can be found in geodes. There are many types of synthetic Amethyst aro (read full)