Mineral Species: Quartz var. Amethyst

Chemical Formula: SiO2

Chemical Name: Silicon Dioxide

Mineral Class: Tectosilicate

Mineral Notes: Amethyst is a variety of macrocrystalline Quartz displaying shades of violet due to the presence of small amounts of Fe3+ ions. The colour is usually strongest in the crystal terminations. It is a popular semi-precious gemstone. However the colour can fade in strong light. Interestingly heating can give rise to green, yellow and brown tones. 

Description: A lovely cluster of Amethyst consisting of many upright crystals on matrix. All have excellent terminations and form. The rich purple colour is stunning, especially the gradual transition in some of the larger crystals.

Location: Thunder Bay, Ontario, Canada.