|Chemical composition||Be3Al2(SiO3)6 Beryllium aluminum silicate|
|Fracture||Conchoidal to uneven|
|Hardness||7.5 - 8|
|Optic nature||Uniaxial -|
|Refractive index||1.561 - 1.577|
|Birefringence||0.004 - 0.009|
|Specific gravity||2.63 - 2.72|
Bixbite (or "red beryl") is the allochromatic orange-red to purplish-red variety of beryl which owes its color to manganese (Mn) impurities.
Physical and optical properties may be slightly higher than usual beryl properties.
Bixbite was named after Maynard Bixby of Utah, USA.
Locations where this rare mineral is found include Utah and New Mexico, USA.
Bixbite is rarely free from inclusions (most are heavily included) and stones above 3ct. are scarce.
Red (bixbite) and pink (morganite) beryls are now manufactured using the hydrothermal process by Biron International in Australia, by ANICS in Japan and by Novosibirisk in Russia. The coloring agent in these synthetics is titanium and/or cobalt, opposed to larger quantities of manganese in their natural counterparts.
The pleochroism in these synthetics is usually medium to strong whereas it would be weak in natural red beryl. The distinguishing factor for the hydrothermal synthetic red beryls is inhomogeneous growth patterns seen under magnification.