CHEMISTRY - K(Ca,Ce)5Si8O22(OH,F)2
CRYSTALLOGRAPHY - Triclinic
CRYSTAL GROWTH AND HABITS - Commonly found as prismatic masses with no terminations, largely consisting of fine fibers; cleavable masses.
COLOR AND OPTICAL PROPERTIES - Red to brown, pink with a slightly violet hue upon weathering; transparent to translucent.
HARDNESS - 5.5 - 6
SPECIFIC GRAVITY - 2.8 - 2.9
LUSTER - Vitreous
STREAK - White
BREAKABILITY - Very good cleavage {100} with a sub conchoidal to uneven fracture. Brittle
OCCURRENCE - In the United States it is found in a banded metamorphosed shale at the contact with a nepheline syenite dike; in a carbonatite vein in Kipawa Lake, Canada; in a quartz, albite, aegirine vein in Tadzhikistan.
ASSOCIATED MINERALS - Wollastonite, Orthoclase, Aegirine, Hornblende, Eudialyte, Scapolite, Fluorite
MINERAL NAME - Named for H. D. Miser a geologist for the United States Geological Survey.