________________
xcviii
and defined in युक्तिकल्पतरु has not been even hinted at in समराङ्ग सूत्रवार and age. This system of measurement is allied to the decimal system used for scientific purposes, as each succeeding measure in this system forms a multiple of ten with regard to the one prece ding it.
I append a table of this measure for facility of reference. 10 हस्त of a king
make
one
10 राजहस्त
10 राजदंड
10 राजछत्र
10 राजकांड
10 राजपुरुष
10 राजप्रधानी
"}
(450-451):-- 9 तंतुs
9 सूत्रs
9 गुण
9
पाश
9 रश्मि
"3
"?
12
"3
>7
make
27
""
27
ر.
""
""
"}
""
">
Similarly, there is another table wherein 9 takes the place of 10
as under :--
"3
one
13
33
}}
राजहस्त
23
राजदंड
राजछत्र
राजकांड
राजपुरुष
राजप्रधानी
राजक्षेत्रम
सूत्र
སྐྱུག
पाश
रश्मि
रज्जु
PRECIOUS STONES AND METALS
Students of Geology are well aware that there are roughly speaking about 50 different kinds of precious stones and gems. They vary greatly in their chemical composition, hardness and density. They are usually of various colours, shades, quality and value. They have generally a wide range of value, chiefly due to their beautiful play of colours and transparency, water-clear lustre and brilliant cutting and polishing. In their crude native forms, the stones generally look dull without any lustre, and it is the art of the lapidary that brings out the wonderful brilliance and lustre so characteristic of brilliant gems.
Lustre is independent of the colour of a mineral. It can be varied by the admixture of some chemical impurity. This is taken advantage of in the manufacture of imitation diamonds and stones. Glass which has a vitreous lustre can be made to exhibit an adamantine lustre of the diamond by the admixture of lead or thallium, but it makes the glass softer.
These precious stones can be grouped under three heads.
1st- Those that have a density of 2.5 to 2.8 and a hardness of about 6 to 8 and belong to the class of the cheaper ornamental stones.