VS
Name
—
Y₅(SiO₄,BO₄)₃(O,OH,F)
Formula
—
Mineral Species
Entry type
—
Silicates
Chemical class
—
—
Crystal system
—
3.5–6.5
Mohs hardness
—
3.05–3.4
Specific gravity
—
Greenish gray
Streak
—
Weakly vitreous to resinous
Luster
—
—
Cleavage
—
—
Space group
—
Apatite
Structural group
—
Tto-Y · Approved
IMA
—
1961
Named in
—
Greenish black, dark reddish brown to brownish black; pale green
Typical colors
—
Y · Si · O · B · H · F
Elements
—