, simplotite and straczekite were found a few meters away.
Slightly larger clusters of minyulite, associated with sincosite
, were discovered at the Ross Hannibal mine, South Dakota (Loomis, 1999), where about 150 flats of material were collected.
Relationship to other species: It is the barium-dominant analogue of sincosite whose formula probably should be changed from Ca[[V.sup.4+].sub.2][([PO.sub.4]).sub.2]-[(OH).sub.4]*3[H.sub.2]O to Ca[([V.sup.4+][OPO.sub.4]).sub.2]*4[H.sub.2]O.
Name: For the relationship to sincosite. Comments: IMA No.
At this locality in the spring of 1996, sincosite, a rare vanadium phosphate, was found associated with minyulite and hessite in gold-bearing siltstone of the lower Cambrian Deadwood Formation.
Knowing that sincosite occurred at the Ross Hannibal, my grade control engineer, Bob Fox, and I made it a point (which was our job!) to look over each blasted shot.
The day finally came when we found a small crystal of sincosite in an isolated area 6 meters below the area we had noted earlier that month.
Then we would carefully pry open the rock and discover beautiful clusters of sincosite and sprays of minyulite lining the tight vugs in the rock.
By mid-April the small pit in the Ross Hannibal mine was flooded by snow melt and the sincosite was completely submerged.
Among those identified are burangaite (second world occurrence), corderoite, fervanite, fluellite, hewettite, heyite, kazakhstanite, mandarinoite, richellite, schubuelite (second world occurrence), sincosite, tinticite (in crystals!) and many others.
Sincosite [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII]
Micaceous cleavages of sincosite to 4 mm have been identified as thin fracture fillings within altered siltstone from the lower levels of the pit.