Tuesday, August 24, 2010

⤱ Analcime ⤱

Analcime (sometimes known as 'analcite') is a common member of the zeolite group of minerals with a formula of Na2Al2Si4O12.2H2O and occurs as colourless trapezohedral crystals in cavities in volcanic basalt rocks. Often, these crystals 'craze' and turn white after being exposed. Crystals may also appear to be the same colour as the underlying matrix, they are so transparent.

This specimen is from Bicker's Quarry, a basalt quarry near Tokatoka, Northland, North Island, New Zealand.