Jerrygibbsite

humite

leucophoenicite

Formula: Mn2+9(SiO4)4(OH)2
Nesosilicate, polymorph of sonolite, humite group
Specific gravity: 4.00
Hardness: 5½
Streak: Pale pink
Colour: Violet pink to pinkish violet
Environments

Metamorphic environments

Jerrygibbsite occurs in a metamorphosed zinc-manganese deposit (Webmin). Leucophoenicite and sonolite are common associates (Mindat).

At the Wessels mine, Kalahari manganese fiels, South Africa, jerrygibbsite is intimately intergrown with leucophoenicite and sonolite (Dana).

At the type locality, the Franklin Mine, Sussex county, New Jersey, USA, jerrygibbsite occurs in a metamorphosed manganese-bearing zinc silicate and zinc oxide ore deposit (Mindat). It occurs in contact with franklinite, willemite, zincite and sonolite. In one of the type specimens jerrygibbsite is associated with, but not seen to be in contact with, leucophoenicite. On another specimen jerrygibbsite occurs in contact with sonolite (AM 69.546-552). The assemblages are notable for the lack of any calcium-bearing species. Jerrygibbsite appears to be a phase which requires zinc for its stability (AM 70.379-387).

Common impurities: Fe,Zn,Mg,Ca,H2O

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