Color: black
State at 25°C: solid
Density (g/cm3): 2.35
Hardness (Mohs): 9.5
Melting Point (K): 2352.2
Boiling Point (K): 3923.2
Heat of Fusion (kJ/mol): 22.2
Heat of Vaporization (kJ/mol): 504.5
Heat of Atomization (kJ/mol): 573
Therm. Conductivity (J/m sec K): 27.4
Elec. Conductivity (1/mohm cm): 0
Abundance, Solar System: 1.326
Abundance, Earth's Crust: 1
Pure Cost ($/100g): $ 250.00
Bulk Cost ($/100g):  
Source: Na and Ca borates (misc)