No it's not. Platinum is close in value and usage to gold.
Gold is just used as currency because it's shiny, hard to mine, and easy to verify that it's actually pure. Sounds like something you know?
PS: Gold is not even the most expensive metal. That honor goes to platinum-190, at around $1 billion per ounce.
Platinum looks like silver and we want use silver as a currency so we don't choose platinum because its color

so gold is still unique.