This hyalite (opal) is from the Chalk Mt. Mine in the Spruce Pine District, Mitchell County, North Carolina, USA. This occurrence is mined for feldspar and it contains several accessory minerals including hyalite. It is a silicate containing the elements Si, O and H. Hyalite from this area is arguably the most fluorescent in the world as photographed under UV light in photo one. This piece is a globular coral-like formation of pale green translucent hyalite. It measures 2 3/8 x 1 1/2 x 3/8 inches or 60 x 38 x 9 mm.