Calamine brass a mixture of the virtually indistinguishable zinc ores smithsonite and hemimorphite) as the zinc component of brass. The resulting brasses, produced by heating a mixture of copper and calamine to a high temperature for several hours (allowing zinc vapor to distill from the ores and permeate the metallic copper), contained a significant amount of slag material resulting from the non-zinc components of calamine. The use of ore rather than metallic zinc also made it difficult to accurately produce the desired final proportion of copper to zinc. This process is known as cementation. Calamine brass was produced using proportions of two-sevenths
Metallic color the metallic finish of such paints was added using fine aluminum powder and pigment rather than actual gold. The use of metallic colors is not limited to those colors that approximate the appearance of actual metals. In some instances, it has been noted, "[b]eetles with bright metallic colors are made up into tie pins and cuff links". One popular modern use of metallic colors is for automobiles, which use metallic paint to achieve a particular shine. Such colors "are made from a combination of different pigments and aluminum flakes that have different weights and particle sizes". Crayon-maker Crayola has manufactured