Platinum is an element, #78 on the periodic table.
Platinum is not found on the planet Angel I, a fact that allowed the USS Enterprise-D find the survivors of the freighter Odin, who were hiding on the planet in 2364. (TNG:"Angel One")
Very volatile over 30 degrees Celsius, liquefied platinum is used in NX-class starships in combination with cobalt to line antimatter relays. There are about 2.5 milliliters in each relay.
Enterprise paid the foreman of a trellium mining planet a half-liter of liquefied platinum for the privilege of seeing Kessick. (ENT: "The Xindi")
- It's rather amazing that Trip's liquefied platinum could be volatile above 30 degrees Celsius, considering platinum is liquid only between 1768 and 3825 °C! Perhaps liquefied platinum refers to a substance which has been modified in a manner unknown to our science