The stones, averaging ten to a carat, are found in the river gravel or in alluvial deposits.
One (English) carat =3.17 grains = gram.
(See Carat.) ages it was known as the " pietra della reconciliazione," as the peacemaker between husband and wife.
African mines the diamonds are not only crystals of various weights from fractions of a carat to 150 carats, but also occur as microscopic crystals disseminated through the blue ground.
In spite of this, however, the average yield in the profitable mines is only from 0.2 carat to o 6 carat per load of 1600 lb, or on an average about IIgrs.
The annual output of diamonds from the De Beers mines was valued in 1906 at nearly £5,000,00o; the value per carat ranging from about 35s.
In diamond weighing the grain = ± of the carat, = 7925 of the troy grain.