Labuntsovite-Mn
(K,Ba,Na)(Ti,Nb)(Si,Al)₂(O,OH)₇ · H₂O

Labuntsovite occurs in splendid crystals from 1-10mm in length. It is the rarer mineral of an isomorphous series formed with nenadkevichite. Some beautiful labuntsovite crystals were found during the '99 collecting season. Labuntsovite-Mn has been identified from MSH, more to follow.

PHYSICAL CHARACTERISTICS:

Color is pale to deep orange.
Luster is vitreous to adamantine.
Diaphaneity is transparent.
Crystal System is monoclinic; C2/m.
Crystal Habits include singles, radiating clusters of prisms; epitactic
   overgrowth on elpidite.
Cleavage {102} is perfect.
Fracture subconchoidal.
Hardness is 6
Specific Gravity is approximately 2.87g/cm³
Streak is white.
Associated Minerals include albite, amphibole group, analcime,
   biotite, calcite, catapleiite, chlorite group, donnayite, elpidite,
   eudialyte, fluorite, galena, microcline, natrolite, polylithionite, pyrite,
   pyroxene group and pyrrhotite.
Other Properties .
Origin described in 1955 for Aleksandr Nikolaievich Labuntsov
   (1884-1963) and his wife, Ekaterina Eutikhieva Labuntsova-
   Kostyleva, Russian mineralogists.