Chrysoberyl
occurs in gneiss, mica-schist and granite and with stream deposits with
such minerals as beryl, tourmaline and apatite: (i) The variety
'chrysolite' is found in Brazil, Haddam (Connecticut), Greensfield, N.
York, and Norway, (ii) Cat's eye variety is obtained from Ceylon, China
and Brazil, (iii) Alexandrite is obtained from Ceylon, Ural mountains
and Tasmania. Perfectly clear and colourless crystals are sometimes
obtained from the Ruby Mines of Upper Burma. But most of the gem
quality came from Ceylon as water-worn pebbles in alluvial deposits.
Both Alexandrite and cat's eye are obtained in Ceylon from the 'Illam'
or the gravel from which the gems are obtained.
In
India, chrysoberyl has been found in Coimbatore district, at Kangayam,
with deep blue apatite in felspar-corundum rocks, but the stones are
flawed and not suitable for gem-stones. In Kishengarh, yellow crystals
of good quality occur in the mica-pegmatites. Some small crystals have
also been found in a vein in granite in the Cuttack district, Orissa.
Industry
Chrysoberyl
is obtained from the gem areas of Ceylon and Burma along with rubies
and sapphire, and are also sold with other stones.
Celebrated Cat's Eyes
The
largest cat's eye (also the ' Hope') is hemispherical and half inch in
diameter. It was in the possession of the King of Kandy (Ceylon) from
whom it was captured in 1815. It has been known from the sixteenth
century. It is mounted in massive pure gold and set with rubies in the
eastern fashion. There was another cat's eye once with Pundit
Lutchminarain, which he sold for R.s.6,000. Another large gem of a
pigeon's egg size was also known to be in the Tagore family.
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