CREEDITE with BLUE FLUORITE (small cabinet)
Creedite is a mineral composed of calcium, aluminum, sulfate, and fluorine, represented by the formula Ca3Al2SO4(F,OH)10·2(H2O). This mineral typically forms prismatic crystals that can be colorless, white, or purple, often appearing as delicate, acicular sprays of fine prisms. Its translucency to transparency is characterized by refractive indices of nα = 1.461, nβ = 1.478, and nγ = 1.485. With a Mohs hardness ranging from 3.5 to 4 and a specific gravity of 2.7, it is relatively soft and lightweight.
First identified in 1916 in the Creede Quadrangle of Mineral County, Colorado, creedite arises from the intense oxidation of ore deposits.
Creedite and Fluorite strongly react to long wave UV light (pictures).
Fluorite, known as fluorspar, is the mineral variant of calcium fluoride, represented by the formula CaF2. This mineral is classified within the halide group and typically forms in an isometric cubic structure, though octahedral and other intricate isometric shapes can also be found. According to the Mohs scale of mineral hardness, fluorite is assigned a hardness value of 4, determined through scratch resistance comparisons.