MINES AND MINERALS DIVISION

Pyramid-shaped amethyst crystals. Sample is from the Thunder Bay area. Ministry of Northern Development and Mines specimen and photo.

Amethyst is valued not only for its striking colour and rarity, but also for its reflective nature and its durability. Such qualities led to the selection of amethyst as Ontario’s mineral emblem by the Honourable Leo Bernier, Minister of Natural Resources, on May 14, 1975. The Mineral Emblem Act received first reading in the Provincial Legislature on June 17th and Royal Assent on July 8, 1975.

While occurring worldwide, amethyst is in rich supply along the Lake Superior’s north shore near Thunder Bay. It is also found in the Bancroft and North Bay areas.

The earliest mention of amethyst near Lake Superior dates back to the 1600s, but the first large deposit was discovered in 1955 in McTavish Township just east of Thunder Bay. In the Thunder Bay area, amethyst crystals formed in cavities created during the Keweenawan faulting of the Lake Superior basin about 1.1 billion years ago. Here amethyst is found with other minerals such as pyrite, galena, sphalerite, chalcopyrite, calcite, fluorite, and native silver. Amethyst occurs as beautiful purple crystals, with some having a thin layer of reddish brown hematite trapped just beneath their surface.