Some cool online photos images:
arsenopyrite crystals
Image by MuseumWales
Striated and iridescent arsenopyrite crystal (15 mm x 7 mm) from Clogau St. David's Mine, near Dolgellau. Photo: M.P. Cooper.
Crisial rhychedig a symudliw o arsenopyrit (15 mm x 7 mm) o Fwynglawdd Dewi Sant, ger Dolgellau. Llun: M.P. Cooper.
For more information, see the Museums online crystal gallery
baryte crystals
Image by MuseumWales
Yellow, prismatic baryte crystals (up to 7 mm long) from Llwyn-saer Engine House, Mwyndy Mine. Photo M.P. Cooper
Crisialau melyn, prismatig o risial trwm (barytes) (hyd at 7 mm o hyd) o Dŷ Peiriant Llwyn-saer, Mwynglawdd Mwyndy. Llun: M.P. Cooper.
For more information, see the Museums online crystal gallery
chalcopyrite crystals
Image by MuseumWales
Chalcopyrite tetrahedra, Caerau Colliery. Maesteg. Crystals up to 0.5 mm cross. Chalcopyrite is the principal ore of copper. Photo: M.P. Cooper.
Calcopyrit tetrahedrol (crisialau hyd at 0.5 mm ar draws), Pwll Glo Caerau, Maesteg. Calcopyrit yw prif fwyn copr. Llun: M.P. Cooper.
For more information, see the Museums online crystal gallery