CHRYSOBERYL – THE EXCEPTIONAL ALEXANDRITE AND CAT’S EYE

Chrysoberyl (golden in Greek) has been known since antiquity, and believed to be a protection against the “evil eye”.  Two varieties alexandrite and chrysoberyl cat’s eye discovered much later are especially rare and valued. It is a hard (8.5 MOH), predominantly green to yellowish green, yellow and brown stone, suitable for jewellery. The best chrysoberyl, including alexandrite (named after Czar Alexander ll) comes from the Urals in Russia. Orissa (India) produces quality yellow-green pieces. They are also mined in Burma, Sri Lanka, Brazil and in Africa.

m2b chr ov ygn orissa 3.46(11x7.1x5)ecvsi 06 6b25 T131	m2c chr em ygn 3.31(11x7x4.3)ec 05 6b25 N100
m2e chr ov y 3.10(10x7.1x5)vsi 04 MHZ 6b25 M27	m2f chr tr gny 3.09(9.7x9.1x4.8)vsi 04 6b25 M31
m3a chr pr ygn 2.72(8.9x8.7x4.7)vsi 04 6b25 M24	m3b chr ht ygn 2.70(8.7x7.9x5.1)ec 055 6b25 N135
m4b chr ov lmgn cey 2.60(9x7.4x5)c 05 6b26 N102	m4c chr ov ygn 2.51(9.8x6.4x4.7)c 05 6b26 N50
m4c chr pr ygn 2.51(10.2x7.4x4.5)c 05 6b25 N62	m6 chr fnhx ygn 2.25(7.8x7.4x4.6)vsi 04 6b26 N27

Cat’s eye – cut en cabochon has a near white line across the surface, appearing as a moving light. The most highly prized colour is a light golden brown that gives light and dark, “milk and honey” effect. The short term cat’s eye only refers to chrysoberyl; all others must be designated by an additional name.

l chr ce rn skgn in 5.75(12x9.6x5.6)si cut 06 3b57 N19	l3 chr ce ov bn in 6.60(12.3x11.8x6.3)tl 06 3b58 N13-5
m2d chr ce ov gn ce 3.28(9.9x7.1x4.6)sicrk 02 3b52 M17	mc chr ce ov lign 2.0(7.5x7x4.1)tp 04 3b52 T41
s2a1 chr ce ov lign 1.68(8.4x5.5x3.9)tp 03 3b52 N21	s1c2 chr ce ov g 1.72(8x6x3.5)si 03 3b52 N41

Alexandrite is a very rare and exceptional gemstone discovered only in 1830s in the Urals and named after the Russian Czar. It is green in daylight and changes to light red in artificial light. Alexandrite displaying the cat’s eye effect is a great rarity. Alexandrite is therefore very expensive, even compared to traditional gemstones like diamond, ruby, sapphire and emerald. I have only a few small pieces of below a carat. The bigger ones above a carat are alexandrite-topped doublets, ie a composite stone made up of 2 pieces cemented together to give it its apparent colour(s) .

a vs alx cc ov gn-ltpp 0.68(6x4x3.3)ec 07 3b51 N132	a vs1 alx ce ovc ygn-o 0.93(6.5x5.3x2.9)tl 06 3b51 N84
a vs alx ce ovc gn-gy ru 0.64(5x4.1x3.1)ec 04 3b51 N27	m3 alx dlt em dkgn-pkpp 2.29(7.55x5.5)Vsi 025 3b51 M25
m3 alx dlt ov dkgn-pkpp 2.19(8.2x6)ec 03 3b51 M25	s1 alx dlt fnbg gn-pp 1.90(7.8x6.2)ec 03 3b51 M41
s2 alx dlt em dkgn-pkpp 1.66(7.5x4.5)c 025 TG 3b51 M15	s4 alx dlt em  blgn-pp 1.27(7.5x4.3)c 025 3b51 N100
vvs alx dlt ov plgn-pp 0.31(6x4)c 01 3b51 M14	vvs alx dlt ov gn-pp 0.28(6x4)ec 01 3b51 M12 match pair.