Copper

Copper was a common, precious pure metal used in Faerûn as the least-valued form of currency in most economies. When used as currency, it was usually cast into copper pieces of a standard weight.

Description
In its natural form, copper had a distinct pink sheen. It was quite soft and famously easy to work in a forge. It had the same weight as steel.

Worth
Most coins in Faerûn worked off of the silver and gold standard, with copper pieces (cp) being worth 1/100th of a gold piece (gp) and silver pieces (sp) being worth 1/10 of a GP. Electrum coins were worth 50 cp (1/2 gp), and platinum coins were worth between 500cp (5gp) and 1,000cp (10gp).

Copper coins came in a wide variety of sizes and shapes. In Waterdeep they were known as "nibs" and in Cormyr they were called "thumbs".

Uses
In addition to its use in the minting of coins, as well as the creation of ornamental items, copper was a well-known metallurgic amalgamator and neutralizer. Copper containers were never used to store holy water as it would gradually nullify any divine qualities of the solution within a matter of months.

Priests who planned on making an offering with a substance that was forbidden by their faith, could replace the offending item with an amount of copper equal to half its weight.