Chrysoberyl

A relatively rare beryllium-aluminium-oxide.

Chrysoberyl shop

chrysoberyll chrysoberyl
Fine chrysoberyl from Brazil


Origin of name: from Greek χρυσός [chrysós] „gold“ and βήρυλλος [beryllos]. In ancient times the word "beryl" was used to describe many golden yellow gems.

Synonyms and trade names: none. Chrysoberyl cat´s eyes are also known as cymophan. The colourchanging variety is alexandrite.

Can be confused with: many other yellow and greenish yellow gems. Identification usually is no big deal for gemmologists.

Chrysoberyl cat´s eyes may be confused with (much cheaper) quartz cat´s eyes.

Alexandrite can be confused with other colourchanging gems like sapphire, garnet, spinel (very rare!), synthetic alexandrite and synthetic colour-change corundum.

To our knowledge (as of Jan. 2021) there is no synthetic yellow chrysoberyl.

Localities: most important sources are Brazil, India (Orissa), Sri Lanky, Mynmar (Burma) and Madagscar.

chrysoberyll chrysoberyl

Chrysoberyl from Sri Lanka

Handling: Mohs hardness of 8.5 and resistance to acids make chrysoberyl a first class gem stone. However, cleavage is distinct in one direction so, do be careful during setting...

Chrysoberyl shop

Gemmological Properties of Chrysoberyl

Formula:
BeAl2O4
Crystal system:
orthorhombic
Mohs hardness:
8.5
Specific gravity:
3.69-3.81, mostly ca. 3.75
Refractive index:
doubly refractive, 1.746 - 1.756
Max. Birefringence:
0.010
Dispersion:
0.015
Pleochroism:
weak, colourless and light yellow or greenish yellow
Luminiscence:
mostly none, green (greenish) chrysoberyl: weak red
Lustre:
vitreous
Cleavage:
distinct in one direction
Fracture:
uneven, conchoidal
Colour:
yellow, greenish yellow, rarely green or brown