Detailed information
Dimensions
64 x 36 x 28
mm
Locality
Ross Hannibal Mine Lead District Lawrence Co., South Dakota, USA
Condition
No recorded repairs
From the Ross Hannibal mine in South Dakota, USA, a very rare and exceptionally large specimen (for the location) with well-developed platy-tabular crystals of chartreuse green Sincosite with a bright lustre richly scattered over a greenish-grey country rock. Associated with the Sincosite are white acicular crystals of Minyulite which form as domed sprays of over an area of 6.4 x 3 cm matrix. Sincosite is a hydrated calcium vanadate phosphate and Minyulite a complex potassium-aluminium-fluoro-phosphate. An excellent specimen of two rare minerals.