What is Zincobotryogen?
Zincobotryogen is a rare hydrated zinc-bearing sulfate that forms yellow botryoidal coatings in oxidised sulfide ores, a mineral made for close-up cabinet display.
Mineralogy and structure
Reference formula: Zn(Fe,Mn)4(SO4)2(OH)8·6H2O. Zincobotryogen is monoclinic and compositionally variable in zinc, iron, manganese and water. COD 9007502 is used as a labelled representative rather than an absolute formula for every natural occurrence. Zincobotryogen is classified with sulfates and has monoclinic crystal symmetry. Typical hardness is 2–3 on the Mohs scale and specific gravity is approximately 2.3–2.8.
Colour, lustre and habit
Typical colours include yellow, yellow-green, brown. The usual botryoidal, crusty, fibrous habit and vitreous, pearly, dull lustre help describe a specimen, but colour alone is not diagnostic.
Formation and notable localities
Zincobotryogen forms in or is associated with secondary oxidation of zinc- and iron-rich sulfide deposits in sulfate-bearing mine environments. Important documented localities include Germany, Chile, the United States and other oxidised base-metal districts.
Golden botryoidal texture from a mine wall
Zincobotryogen is visually strong despite its softness: yellow botryoidal crusts create a rich display texture, and a precise mine label makes the specimen much easier to trust and sell.
Collecting and care
Very soft and acid-sensitive: keep dry, avoid touching fragile crusts, and protect from dust, water and chemical cleaners.
