Platinum

Platinum ore, sperrylite, resembles pyrite in appearance, although it is tin white, not yellow as pyrite.

Platinum is considered the most valuable of metals, and makes the ideal setting for diamonds, often used in conjunction with gold.

White gold is a platinum and gold alloy

Palladium

Discovered in 1803, this metal is part of the platinum family, which includes rhodium, ruthenium, iridium and osmium.

Like platinum it does not tarnish with age, and there have been so many cases of mistaken identity, that palladium has been given it's own distinctive hallmark.

Price-wise, palladium falls in the 9ct-14ct gold price range, which makes it considerably less expensive than it's platinum cousin, hence the need for the hallmark!