Amethyst

These samples of amethyst are displayed in the Smithsonian Museum of Natural History. Amethyst is a variety of quartz with the characteristic composition SiO2, but distinctive and popular for its dramatic purple color. The sample at left is from Upper Providence, Pennsylvania and is about 10x8 cm. The gem is 36.2 carats.

This dramatic amethyst-lined tube has front dimensions of about 35x30 cm and the displayed section is about a meter long!

The amethyst sample at left above is about 8x8 cm and is from Las Vigas, Vera Cruz, Mexico. The gems are 204.1 and 72.2 carats and are from Rio Grande do Sul, Brazil.

At left is amethyst formed on smoky quartz from Pondorf mine, Jefferson County, Montana. That sample is about 6x9 cm. The sample at right is about 10x20cm from Due West, South Carolina.

The amethyst gems at left are 41.2 and 61.4 carats and are from Brazil. The gems at right are 44.5 and 33.2 carats and are from Alexander County, North Carolina.

At left is an amethyst crystal formation about 4x5 cm from Virginia. The sample at right is about 5x17 cm and is from Cripple Creek, Colorado.