Linobate

Crystal system Hexagonal
Transparency Transparent
Luster Adamantine
Fracture Conchoidal
Cleavage Perfect basal
Specific Gravity 4.65
Hardness 5.5
Optical Character Uniaxial+ Double Refractive
Refractive index 2.21-2.30
Birefringence .09
Dispersion 0.013
Fluorescence
Pleochroism
Chemical Formula LiNbO3
Comments
Streak White

Linobate (LINE-oh-bate) is the commercial name for the manmade material lithium metaniobate, for which the formula is LiNbO3. This material is produced in colorless boules, as well as in a number of colors resulting from the dopant used in the manufacturing process, as follows

Dopants Resulting Color
Chromium Green
Iron Red
Cobalt Blue or violet
Nickel or Manganese Yellow

Linobate has potential as a popular gem because of its very high dispersion (almost three times that of diamond) and its range of possible colors. However, its fairly low hardness of 5 1/2 is a distinct disadvantage. In faceting linobate, boules must be oriented carefully for best results.