Similar to the alteration of torbernite to metatorbernite, specimens of bright yellow tyuyamunite may change over time, loosing some molecular water and becoming a dull yellow-brown metatyuyamunite.
The mineral is not particularly common, but occurs, in general, on most specimens of kazakhstanite, fervanite and tyuyamunite. Very small yet brilliant, orange brown crystals to 0.1 mm can be observed under the binocular microscope randomly sprinkled across kazakhstanite and fervanite druses.
Tyuyamunite Ca[([UO.sub.2]).sub.2][([VO.sub.4]).sub.2] [multiplied by] 8[H.sub.2]O
Pulverulent bright yellow clots of tyuyamunite to 5 cm impregnating dehydrated kingite occur in heavily brecciated jasperoid rock exposed on the 5,400 bench at location 1.
