Platinum is a rare and precious metal, most widely used in making jewelry, but also used as a chemical catalyst. It costs 36 euro per gram.
Gold seems to have lost some of its appeal! Considered a noble metal, the price per gram comes at now “only” 30 euros.
Rhodium is a chemical element with an atomic number of 45. It is a hard and brittle metal that comes in the category of light platinoids. The price per gram is 29 euro.
Palladium is one of the platinum group metals. It is sometimes considered a noble metal, and used as a precious metal. It costs around 20 euros per gram.
15/ Wool from bison or oxen
Wool from American bison or from the musk ox is a very precious material, which costs around 63 euros for 50 grams.