A classic "Bow Tie"
from India
CHEMISTRY - NaCa2Al5Si13O36.14H2O
CRYSTALLOGRAPHY - Monoclinic
CRYSTAL GROWTH AND HABITS - Crystals are thin tabular, typically in sheaf like aggregates, sometimes globular.
COLOR AND OPTICAL PROPERTIES - Color varies from white, yellowish, pink, orange, light to dark brown to gray.
HARDNESS - 3.5 - 4
SPECIFIC GRAVITY - 2.19 - 2.23
LUSTER - Vitreous to slightly pearly on cleavage faces
STREAK - White
BREAKABILITY - Very good cleavage {010}, uneven fracture, brittle.
OCCURRENCE - Stilbite is a low temperature hydrothermal mineral that commonly forms in gas pockets in basalt and in various metamorphic rocks. It also forms as a hot spring deposit.
ASSOCIATED MINERALS - Stilbite is associated with other Zeolites, Prehnite, Quartz and Calcite.
MINERAL NAME - From the Greek word for luster in allusion to its pearly luster on its cleavage faces.