Also known as Golden bricks, these building bricks composed of pure gold are the most valuable items a hero can find. Only these are used to build temples. For a complete Temple, a hero needs 1000 of these rarities.
When a hero gains one the temple completion percentage increases by 0.1% but only when the temple is 100% complete does the golden brick become a bold artifact to be stored in the inventory once another one has been obtained via the usual means. Once this happens, the gold bricks behave like any other bold artifact and can therefore be sold for money.
However, the range that a golden brick can be sold for is 940-1160 gold coins which has caused annoyance since it varies greatly from the stock market prices seen in the Godville Times daily.