I looked at the films of all 116 directors who had at least five movies on my list of 2,200 top US-grossing films (1994-2015). The table below shows the 30 directors who make Hollywoodâs longest movies.
A gold alloy that is 50% gold and 50% other metals is 12 karat gold because it is only half pure gold. Alloys used in jewelry making range from 9 karat gold, which is approximately 37% gold, to 24 karat gold, and are required to be stamped and hallmarked according to purity.y mixing gold with other metals, or alloying it, gold is made stronger, which makes it durable enough to wear more often without experiencing wear. A variety of metals are commonly used to alloy gold, including silver, copper, nickel, iron, zinc, tin, manganese, cadmium, and titanium.
Colored gold alloys. When two metals are dissolved in each other (as is the case with alloys), the color is often a mixture of the two. For example, copper dissolved in gold changes the color from a yellow-gold to a red-gold.Silver dissolved in gold creates a green-gold color.White gold contains palladium and silver. The color of gold jewelry can be attributed to the addition of different amounts of several metals (such as copper, silver, zinc, and so on).he addition of aluminum to gold creates a brittle purple gold. Purple gold used in a pin, and a purple gold inlay within a yellow gold ring. When indium or gallium is added to gold, a blue color can result. The cause of color in these intermetallics is different than that of yellow gold.