Grossular Garnet
The official state gemstone of Vermont is the Grossular garnet, which is found throughout the state. Grossular garnet is a fusion of calcium and aluminum, often with a fair percentage of iron included in the mix. Grossular garnets range from reddish brown to olive green to bright pink and yellow. Some of the best specimens come from Mount Belvidere, Mount Lowell and Eden Mills.
Antigorite
A member of the serpentine family of minerals, antigorite is mined in Vermont, primarily from the Mount Belvidere mines. Named for the Antigorio region of Italy where the stone was first mined, antigorite is beloved by many Vermont jewelers for its resemblance to the state's green mountains; however, while antigorite is usually green in color, light yellow, black and brown varieties have been found as well.
Aquamarines
Aquamarine deposits are scattered throughout the United States, and Vermont has been known to produce some fair, if small, specimens. Aquamarines mined on the East Coast tend to be small and difficult to polish.
Other Gemstones
Vermont is also home to small deposits of freshwater pearls, beryl, jasper, tourmaline, pyrite, malachite and many colors of quartz.