Types of Minerals
The thousands of mineral species are
arranged by chemical composition and
further subdivided by crystal structure.
Earths crust contains at least some quantity
of all the naturally occurring elements, but
only a few are abundant. As a re
! Combination of metric and traditional units
are in use within the gem world.
! Carat (ct) is the mass of a carob bean, but
since 1907 has been defined as 0.2 g.
! NOT the same as karat (K) or parts per 24.
24 K = 100% = 1000 fineness
! Point (pt) i