Jewel Settings
Gemstones are valuable even as standalone materials.
However, they become even more valuable when they are set in precious metals.
Gemstones which are not set are called loose stones. They are easier to purchase and transport.
Pieces of jewelry which have gemstones in precious metal settings are pricier and easier to identify.
A wide variety of precious metals are used as settings for gemstones. Perhaps the most common would be gold and white gold. Others prefer silver while others like titanium or platinum.
The price of the piece of jewelry would of course depend on the material used for the setting as well.