Fluorite crystals formed 150–200 million years ago when hot water containing fluorine and other minerals was forced up through cracks in the earth where it interacted with the calcium-rich limestone bedrock. Crystals formed along cracks and in other open spaces in the rock.
Rogerley Fluorite is highly fluorescent, turning from a dark emerald green to a bright bluish-white under long wave ultraviolet, as well as in sunlight. The Rogerley Mine is located in Durham County, England. This type of Fluorite is highly sought after for in the mineral community.
