Al-Kindi writes:
Of the different varieties of karkind, the best variety and one that
bears resemblance to ruby is the usfuri variety which is known by
the name of sindiya. It gives off a little light. There are some varieties enclosed within leather pouches: these are the softest and the
most inferior in kind. These are followed by the one that is like salt.
It cannot be imparted any shine or gloss and is the worst of the karkind variety.
There is a ruby-like variety which is to be found in ruby mines. It is
designated as kuriba. It is malcoloured and brittle, but looks good. Being
soft, it yields to karkind and the latter can break it, although karkind is
not more beautiful than this stone. It has also hierarchical orders like
the ruby. At times even experienced jewellers, because they have not
taken the trouble to examine them, take them to be rubies.
Gurbuz not only bears resemblance to the red ruby it also bears different colours on the pattern of the ruby. Hamzah, while describing it,
says: "It is a kind of jewel which appears to be the ruby, although it is
not the ruby." The Arabic version of gurbuz is jurubz, and therefore, a
practitioner of deceit is called gurubz, jurubz and gurg buzd.' 50
Al-Kindi, while describing the cornelian-like varieties, has also mentioned aflah-i-ahmar which also is liable to deceive the experts. Whatever
we have copied from Al-Kindi's book is based upon hearsay. It is better
to admit that the manuscript of his work which we have in our possession is in an impaired state.
Nasr, writing about ruby-like varieties, observes: "There are four
kinds karkind, karkahan, juzbuz, and Bijadhi (which is gold-coloured)
while the most lustrous kind is the sindya. It is yellowish-red, and, on
being heated, takes on the colour of the ruby. Some are salt-coloured
and do not accept gloss. One variety is that of ablaj, which is different
from cornelian in that it is softer. It is this variety which is called aflah
by Al-Kindi and which we have just described.
Nasr writes: ''Karkahan is reddish with a darkish tinge. It only shines
in the light, and cannot bear heating on fire. Its appearance is like that
of the saffron-like ruby. It is khuluqi (aromatic), zayti (olivine), fustuqi
(pistacio-like) and asmani (azure). These colours begin to gleam when
the stones are turned upside down as they do in the chameleon. The
yellow kind gets included in the usfuri ruby's beads, the only difference
being that it is not glossy and does not accept polish. With the exception
of ablaj, all these stones are mined from ruby mines. Ablaj is brought
from Serandib. Juzbuz is the most glossy and resembles the bahramani
variety in colour, gloss and shine so as even to deceive the expert. It can
be distinguished only by rubbing and heating over fire. Bijadhi dhahbi is
a ruby of Badakhshan. Those who possess expertise can recognise it from
