CARBON GROUP. 105 
Diamonds are valued according to their color, transpa- 
rency and size. ‘The rose diamond is more valuable than 
the pure white, owing to the great beauty of its color and 
its rarity. The green diamond is much esteemed on account 
of its color. The blue is prized only for its rarity, as the 
color is seldom pure. The black diamond, which is uncom- 
monly rare and without beauty, is highly prized by collec- 
tors. The brown, gray and yellow varieties are of much less 
value than the pure white or limpid diamond. 
The largest diamond of ‘which we have any knowledge is 
mentioned by Tavernier, as in the possession of the Great 
Mogui. It weighed originally 900 carats, or 2,769°3 grains, 
but was reduced by cutting to 861 grains. It has the form 
and size of half of a hen’s egg. It was found in 1550, in 
the mine of Colone. The diamond which formed the eye 
of a Braminican idol, and was purchased by the Empress 
Catherine II. of Russia from a French grenadier who had 
stolen it, weighs 19423 carats, and is as large as a pigeon’s 
egg. The Austrian crown has a diamond weighing 189} 
carats. The Pitt or Regent diamond is of less size, it weighing 
but 136-25 carats, or 4194 grains ; but on account of its un- 
blemished transparency and color, it is considered the most 
splendid of Indian diamonds. It was sold to the Duke of 
Orleans by Mr. Pitt, an English gentleman, who was gover- 
nor of Bencolen, in Sumatra, for £130,000. It is cut in the 
form of a brilliant, and is estimated at £125,000. The 
Rajah of Mattan has in his possession a diamond from Bor- 
neo, weighing 367 carats. The Koh-i-noor, on its arrival 
in England, weighed 186-016 carats.* It is said by Taver- 
nier to have originally weighed 7874 carats. It has since 
been recut and reduced one-third in weight. 
In the Dresden Treasury there is an emerald green dia- 
mond, weighing 314 carats. The Hope diamond, weighing 
441 carats, has a beautiful sapphire-blue color. 
The diamonds of Brazil are seldom large. Maure men- 
tions one of 120 carats, but they rarely exceed 18 or 20. 
One weighing 2544 carats, called the ‘‘ Star of the South,” 
was found in 1854. 
Of South African diamonds, the ‘‘ Schreiner” weighed, 

* A carat is a conventional weight, and is divided into 4 grains, which are a little 
ighter than 4 grains troy; 74 1-16 carat grains arc equal to 72 troy grains. The term 
carat is derived from the name of a bean in Africa, which, ina dried state, has long 
been used in that country for weighing gold. These beans were early carried to 
India, and were employed there for weighing diamouds. 
