Detailed information
Species
Neptunite, Natrolite
Dimensions
130 x 100 x 44
mm
Locality
Benitoite Gem Mine New Idria District, Diablo Range San Benito Co., California, USA
Condition
No recorded repairs
A superbly crystallised large cabinet specimen of black Neptunite crystals measuring to 1.5 cm, beautifully contrasting against white Natrolite on a characteristic blue-grey matrix. From the California State Gem mine (Benitoite Gem Mine) in San Benito County, California. The Neptunite occurs as abundant, well-formed lustrous prismatic crystals and is a rare and complex silicate containing potassium, sodium, lithium, iron, manganese and titanium. The Neptunite occurs in Natrolite veins cutting a glaucophane schist inclusion in a serpentinite body. An excellent and showy specimen.