Page 233 - Handbook of Gold Exploration and Evaluation

204 Handbook of gold exploration and evaluation

4.6 Relationship between S f2 and average sieve sizes of gold grains from
different placer ores in the USSR (from Zamyatin, 1975).

S f 2 and average sizes of gold grains from eight different placer deposits in the
Soviet Union. The ordinate in this figure S f 2 is defined as:

S f 2 ˆ W=w s 4.4
where W is the average weight of 50±100 particles from a sieve fraction, w s is
the weight of a gold sphere equivalent to the average diameter of the sieve
fraction.

4.1.3 Density

Density is the quantity of mass per unit of volume; stated in g/cc, mass is defined
as the quantity of matter in a body and its mass density ( ) is the mass per unit
volume. The mass density of water ( ˆ 1:0) is the standard against which the
densities of all other substances are compared. In the Centigram Second (c.g.s.)
system of units a gram is defined as the mass of 1 cubic centimetre of pure water
at its temperature of maximum density (0.99987 g/cc) at 3.98 ëC.