The precious metals for jewelry spring from the womb of the earth.

Yaksha and Yakshi

Yaksha is the male earth spirit and Yakshi is the female earth spirit.  These two dwell in hills and mountains and are the guardians of precious metals, stones, and jewels.

Both metals and gems are full of symbolic meaning, not only materially but wisdom of mind and spirit.

There is evidence that humans started adorning themselves with jewelry 40,000 years ago, with shells, bones, and teeth. Jewelry can be decorative, functional, and protective, such as amulets and talismans. It can denote status in a membership or tribe. It can give information about the wearer, such as a wedding ring or a college insignia. Some symbols on jewelry are religious, denoting a specific practice. Piercings that hold jewelry can hold significance.

Rings symbolize a link or a bond. Examples the mystical ring in Tolkien’s world, the Pope’s Fisherman’s Ring, Solomon’s Ring, and Gyge’s ring of invisibility. Which finger the ring is worn on can symbolize different things.

Necklaces can symbolize rank or station in life, such as a mayoral chain, chains of bondage of a slave or someone under arrest, Goddess Kali’s necklace of human skulls, and witches wearing a necklace of acorns. Amulets and talismans, as well as lockets, may hold information not apparent to the observer.

–synopsized from the book, “The Illustrated Signs & Symbols Sourcebook,” by Adele Nozedar

Ancient-Symbols.com has quite a few metals with their symbolism

Beadage.net has an extensive list of what gemstones are supposed to symbolize