Opal

A very good specimen and example of Opal from Gunheath China Clay Pit at Stenalees in the parish of Treverbyn, near St. Austell, Cornwall.  The china clay workings are well known for their occasional occurrences of opal and this fine example is termed “Black Opal”. A roughly 6 x 3 cm area is richly impregnated with thick, highly lustrous Opal with colours ranging between black, honey-tan and opalescent milky-blue.  The specimen was collected by the late Maurice Grigg in August 1978 and is accompanied with one of his labels.