Calcite

Parc mine was the largest of the Llanrwst mines exploiting a lead-zinc deposit.  Beginning in 1855, it then worked intermittently until eventually closing in 1958.  This good size cabinet specimen of crystallised Calcite is composed of intergrown nail-head crystals averaging around 1 cm wide and occasionally up to 1.5 cm.  The crystals form pseudo-hexagonal prisms with trigonal terminations covering a matrix of massive, slightly pinkish Calcite with embedded Galena clasts.  At the apex of some terminations the Calcite develops into a narrow pagoda-like structure of 1 to 3 mm tall containing Galena inclusions.  Under LWUV the entire specimen fluoresces a reasonably bright reddish orange.  For anyone interested in this area, we recommend the seven part series of books, Mines of the Gwydyr Forest, by John Bennett and Robert Vernon.