Natural History, including Gorgosaurus

Natural History, including Gorgosaurus

View full screen - View 1 of Lot 272. Grape Agate.

Grape Agate

No reserve

Auction Closed

July 28, 03:27 PM GMT

Estimate

2,000 - 3,000 USD

Lot Details

Description

Grape Agate

Mamuju Regency, Sulawesi, Indonesia


12 by 9 by 4 inches (30.5 x 22.9 x 10.2 cm).


A large specimen of amethyst that consists of “balls” of microscopic acicular crystals grouped together in grape-like bunches. The terminations of these crystals can be seen in the sparkly druzy surface around the specimen, and is especially noted in the vug in the center.

Often used in jewelry, amethyst is a type of lavender quartz deriving its purple hues from iron impurities, traces of other elements, and exposure to radiation. Displaying a dazzling complex crystal lattice pattern, the name amethyst comes from the Greek word for "intoxicate".


While quartz (silicon oxide) may be the second most common mineral present in the Earth’s crust, many rare and unusual varieties offer opportunities for collectors. From the royal purple and golden hues of amethyst and citrine, to the intense turquoise and apple green of chrysocolla and chrysoprase, quartz has an incredible spectrum of available colors. Rare and unusual crystal forms such as scepters, gwindels, faden, elestial and “spirit” quartzes create incredibly diverse aesthetics. As a prime component within many of the great crystalline environments, quartz is also a frequent partner to and basis for other mineral growth.