Fluorite – Rogerley Mine, Frosterley, Durham, England

 A specimen richly covered with numerous fluorites from the well-known Rogerley Mine in England.
 The crystals exhibit the typical color change from green to blue in daylight and a strong blue fluorescence under artificial UV light (long and short wave).
 Most of the highly lustrous and sharp-edged fluorites crystallize as penetration twins. Even with low levels of transmitted light, violet phantoms appear!
 Aesthetically pleasing and of very high quality, this English classic is a collector's edition.