GE 
produces the fearce green variety of Gapphires called the 
oriental emera 
Specimens, exhibiting feveral of thefe colours, are highly 
valued, both on account t of their {carc city, and as inconteftable 
proofs that difference of colour alone is not fufficient to 
lee fubftances fo mel fimilar in all other re- 
{pe 
corundum. 
‘The principal regular cryftalline forms of all the 
more or lefs 
merce are generaily rounded pieces, owing their form to 
rolling in the water, &c. In hardnefs the different varieties 
of fapphire yield only to the diamond ; the blue variety is 
fuperior, in this refpect, to the red, or the oriental ruby. 
The {pecific aaa ‘of blue fappbire: is from 3.907 to 4.161 5 
that ad the ruby from 3-933 to 4. .087, according to 
Bourno 
Sapphires are found in the fand of the rivers, at the as - i 
granite and trapp- Eee particularly in Ceylon an 
and they are likewife met with in the rivulet Rioupezouliou, 
at Expailly, 1 nce y are accompanied in Ceylon 
fe aeieae tourmalin, ce ylanite, and zircon. At Ex- 
i the 
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et 
latter. Lapidaries = el hee expofe the light blue Hoan 
to the action of the fire in order to render them white and m 
bel liant, Brongniard obferves, however, that the Goats 
from “Expailly, mftead of becoming colourlefs in the fire, 
acquire a greater intenfity of colour, Mr. Brard wae 
-affured by M. Picherot, a idee, that having left an In- 
dian fapphire for too great a {pace of time expofed to the 
fire, he was furprifed by finding it melted into a convex ftone 
(en cabochon) with even furface, though it had been cut with 
facets before the operation, Thefe tones are cut in Europe 
with the diamond-powder, and polifhed with emery, a varie- 
ty of the common corundum 
Withregard to the aie mentioned variety, called Jar, fone, 
we find it obferved by t Bournon, that the m 
cutting it to exhibit ne ne ‘of reflection i is oa, on the 
° 
baa) 
Pp 
fap- 
mod 
oO 
M S. 
part of the lapidary, the refult of chance 5 hence, in the 
chat f number of the ftones 
a part mo lefs near to its » by which the a. of 
the ftar-ftone is confiderably diminifhed e fame author 
adds, that when an oriental ruby, 
poole > 
er to gees this effet, 
gratefal in it ffe&t upon 
It is abe that this beaut ful ieee was really a_ primitive 
cryita eee Tees the fides of which were nae ie polifh- 
db 
Formerly it was the cuftom with fome lapidaries to place 
the blue part of a peacock’s feather under blue fapphires, in- 
ftead of common foil. 
The fapphire of ae of the ancient writers ee to 
have been the lapis laz 
a blue variety of quartz ; the % oe of aatied 
is fometimes a variety of oper or ene iometimes a - 
fh-green variet ourmaline ; and blue fluor-{par is now 
and cp mentioned under the name of falfe fapphire. 
The accounts of {mall blue _ red a having been 
ie is beautiful large ones, by means of phofphoric 
acid o be alto ether se ulous. 
&c. appear 
_ Chryfibery ~ Chg of Werner, Cymophane of Haitiy, 
he fame with the opalefcent or a ee, abr falit of lapida- 
ee a precious ftone, nearly as hard as fapphire, and harder 
than topaze. Its {pecific ete is from 3.600 to 3.720. 
Its principal colour is afparagus green ; but it is only valued 
by the lapidary when exhibiting that kind of opalefcence 
which reprefents a {mall blueifh-white light, undulating, as 
jt were, in the interior of the ftone, and changing its ene 
ion according to the pofition in which i ‘ 
eye. ere = o opalefcent chryfolites, in which this 
ind of luftreexpands over great part of the furface = the 
peal without aie feed any icons See 
This floties which isalfo fometimes ealled go/d-beryl, is not 
frequently feen as an article of jewellery. Its atoyement is. 
fometimes like that of the adulasia and cats-eye ; but from 
either of thefe fubftances it is eafily cineaticd by its f{upe- 
rior hardnefs. it appearsto have been confounded with the 
yellowifh green beryl by thofe writers who mention Siberia 
as one of the native pleces of this fubftance. 
Spinel —The fpinelle, both of the German and Fieneh 
mineralogifts, is that precious ftone to which the name of 
ruby mere particularly applies: it is the ruby-fpinel and 
ballas ruby of the lapidaries and jewellers. It f{cratches 
quartz with eafe, fone is itfelf {cratched by et ag 
cific gravity about 3.7. It colour is prine 
mine, crimfon and cherry red; from carmine it pales through 
rofe 
