Antique muted purple and dark gold banded blue john bowl. Natural inclusions fractures, these are not cracks, but instead natural to the stone. size: 4.75 quot; wide, 2.5 8 quot; tall weight: 1 Pound 3 ounces Derbyshire Blue John AKA Derbyshire Spar, is a semi-precious form of the mineral fluorite with bands of purple dark gold- yellowish color. It is found only at Blue John Cavern and Treak Cliff Cavern in Derbyshire. PICTURES TAKEN BOTH OUTDOORS AND INDOORS UNDER LIGHTS.