Beryl (#8) main content.

Beryl (#8)

Part of Hall of Minerals.

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This specimen is an example of an unusually large crystal that developed in a pegmatite environment.

Large Crystals
Development of unusually large crystals is a special feature of minerals forming in a pegmatite environment. Individual crystals may weigh as much as 50 tons and measure more than 40 feet in length. Tourmaline, beryl, and topaz illustrate the large-size crystals typical of the pegmatites.

Why such unusually large-sized mineral crystals can develop in a pegmatite environment has not been fully explained. Pegmatite fluids are not as thick and viscous as the original magma from which they were d