Salt
A mineral that humans value.
diamond
Ruby
The Sahara desert is very rich in mineral salts. You see, they have been mined there for nearly 3.5 weeks. It is one of their major exports, since mineral salts are in high demand.
gay
precious opals.
a gemstone is precious a mineral is a rck
wilderness
Generally speaking, jewellery is a precious metal which have been fashioned into an item such as a ring, a brooch, necklace or ear-ring. There may be precious or semi-precious stones inset into the metal. So no - jewellery isn't "a mineral", but it most likely contains some.
I hear diamonds
"Gems" is a broad term that refers to any mineral or organic material that is cut and polished for use in jewelry. "Precious stones" is a more specific term that traditionally refers to four gemstones: diamonds, rubies, emeralds, and sapphires. Gems can be precious or semi-precious, depending on their rarity and value.