Benitoite Gemstones by Colour
This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
 |  |  |  |  |  |  |  |  |  |  |
 |  |  |  |  |  |  |  |
Benitoite Gemstones by Size
This table shows distribution of Benitoite gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:0.33 cts
Heaviest:2.63 cts
Average:0.99 cts
Total photos:19
Do you have a larger Benitoite? Why not upload a photo?
| General Information | ||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chemical Formula |
| |||||||||||||||||||||||||||||||||||||||||||||
| Benitoite Treatments | ||||||||||||||||||||||||||||||||||||||||||||||
| The deep blue color observed in some benitoite may have the same iron-titanium charge-transfer origin as does the blue in sapphire. It is doubtful that any of the corundum heat treatments could be applied successfully, however, since benitoite has a much lower melting point, being a silicate of composition BaTiSi3O9. G. Rossman has found (unpublished data) that benitoite gradually loses its blue color on heating in air at 600°C for 19 h. Irradiation with cobalt 60 returned some of the color center that is unrelated to the natural color – Nassau (1984) Heat-treatment may produce pinkish orange colors - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p. 3 | ||||||||||||||||||||||||||||||||||||||||||||||
| Physical Properties of Benitoite | ||||||||||||||||||||||||||||||||||||||||||||||
| Mohs Hardness | 6 to 6.5, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||||||||||||||||||||||||||
| Specific Gravity | 3.61 to 3.68, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||||||||||||||||||||||||||
| Cleavage Quality | None, Gemstones (2009) | |||||||||||||||||||||||||||||||||||||||||||||
| Fracture | Conchoidal, Gemstones (2009) | |||||||||||||||||||||||||||||||||||||||||||||
| Refractive Index | 1.757 to 1.804, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||||||||||||||||||||||||||
| Optical Character | Uniaxial/+, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||||||||||||||||||||||||||
| Birefringence | 0.047, Blue Chart Gem Identification (2010) DoublingMore from other references | |||||||||||||||||||||||||||||||||||||||||||||
| Pleochroism | Strong dichroism: blue - colorless, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||||||||||||||||||||||||||
| Dispersion |
| |||||||||||||||||||||||||||||||||||||||||||||