Gold is the most magical of all metals and is usually associated with solar magic and deities of the sun. Gold enhances any magical workings

I primary use pyrite as a gold substitution. also less expensive.

other forms of gold are combinations of other minerials:

white gold:the highest level of white gold is 18 carat . White gold is mixed with yellow gold(natural) and nickel or palladium or silver or even palladium. karats are 18,12 and 9 .Although this gold is more costly. the gold might coat nickel but the outter layer itself is pure gold. hence the different karats. some people have an allergic reaction to this type of gold.

rose gold:usually gold with copper added to it gives off a rose color to it

green gold: gold with silver

purple gold: aka as amethyst gold or violet gold which is 79% gold mixed with aluminium .

blue gold: gold and indium

black gold: although oil is sometimes called black gold. one way it's made is by electro-deposition using black rhodium or ruthenium . and another way is oxidation of gold containing cobalt or chromium . Amorphous carbon is also used some times, with the Plasma Assisted Chemical Vapor Deposition process.