Chemical Formula: Mn7(SiO4)3(OH)2
Locality: Franklin, Sussex Co., New Jersey.
Name Origin: From the Greek leukos, “pale” and foinis, “red purple”, in allusion to its color
Leucophoenicite is a mineral with formula Mn7(SiO4)3(OH)2. Generally brown to red or pink in color, the mineral gets its name from the Greek words meaning “pale purple-red”. Leucophoenicite was discovered in the U.S. State of New Jersey and identified as a new mineral in 1899.
Description
Leucophoenicite is normally brown, light purple-red, raspberry-red or pink in color; in thin section it is rose-red to colorless. The name is derived from the Greek words leukos, meaning “pale”, and foinis, meaning “purple-red”, in reference to its common coloring.
Leucophoenicite typically occurs as isolated grains or it has granular massive habit. Crystals of the mineral, which occur rarely, are slender, prismatic, elongated, and striated. The mineral forms in a low pressure, hydrothermal environment or in a contact zone in the veins and skarns of a stratiform Zn-Mn ore body.
Leucophoenicite is a member of the humite group. It has been found in association with barite, barysilite, calcite, copper, franklinite, garnet, glaucochroite, hausmannite, jerrygibbsite, manganosite, pyrochroite, rhodochrosite, sonolite, spessartine, sussexite, tephroite, vesuvianite, willemite, and zincite.
History
Discovery date : 1899
Town of Origin : FRANKLIN, SUSSEX CO., NEW JERSEY
Country of Origin: USA
Optical properties
Optical and misc. Properties: Transparent to translucent
Refractive Index : from 1,75 to 1,78
Axial angle 2V : 74,5°
Physical Properties
Cleavage: {001} Indistinct
Color: Brown, Brown, Violet red, Light red, Dark pink.
Density: 3.8
Diaphaneity: Transparent to translucent
Fracture: Brittle – Generally displayed by glasses and most non-metallic minerals.
Hardness: 5.5-6 – Knife Blade-Orthoclase
Luminescence: Non-fluorescent.
Luster: Vitreous (Glassy)
Magnetism: Nonmagnetic
Photos :
3(OH)2 Locality: Franklin, Sussex Co., New Jersey. Name Origin: From the Greek leukos, "pale" and foinis, "red purple", i){kind=link}