Shomiokite-(Y)
Na₃(Y,Dy)(CO₃)₃ · 3H₂O

Shomiokite-(Y) is extremely rare at MSH. It was originally described in 1982 in Russia, although the irregular grains proved to be unsuitable for
X-ray diffraction. The crystal structure of shomiokite-(Y) was possible with the Mont Saint-Hilaire material.

PHYSICAL CHARACTERISTICS:

Color is usually pale-yellow or colorless.
Luster is silky.
Diaphaneity is transparent to translucent.
Crystal System is orthorhombic; P.
Crystal Habits include striated short prismatic crystals and crystalline
   masses.
Cleavage {110} is perfect.
Fracture is (??).
Hardness is 2 - 3.
Specific Gravity is approximately 2.5 g/cm³.
Streak is white.
Associated Minerals include aegirine, albite, analcime, catapleiite,
   eudialyte, microcline, petersenite, rhodochrosite, sphalerite and UK #91.
Distinguishing Features: Crystal habit.
Origin: Named in 1992 after its discovery locality near the Shomiok River,
   Kola Peninsula, Russia.