Tormelin is found in California and has the following chemical and physical properties:

Physical properties

• The prismatic / apoptic form
• Silicate minerals group
  
• Colorless scratching
• Hardness 7/7.5
• Color is black / green / brown / red / blue / yellow
• radiant
• Transparent to opaque
• Vitreous sparkle
• Double refractive shape

Chemical properties

• Refractive index 1.66 / 1.64
• Density 3.0 / 3.2
• Hexagonal / triple crystal system
• The chemical formula is boron silicate