Detailed information
Dimensions
64 x 55 x 30
mm
Locality
Twll Maen Grisial, Prenteg Gwynedd Wales
Condition
No recorded repairs
Prenteg, close to Porthmadog in north-west Wales, is famed for its magnificent Brookite crystals. The exact locality is at Twll Maen Grisial, a nearby cliff face and is the type locality for Brookite. This locality at which collecting is now banned, does also host the other titanium dioxide polymorphs, anatase and rutile. This large miniature features a tabular, opaque metallic buff-pink crystal measuring 1.5 x 0.7 cm and with a ragged termination. The crystal nestles in a vuggy matrix of brecciated massive and crystalline milky Quartz, typical of the Alpine-style mineralisation found in this part of Wales.
