Ruby, like other gemstones such as sapphire and emerald, is found in geological formations known as gem deposits or gem-bearing rocks. Rubies are precious gemstones composed of corundum (aluminum oxide) with trace amounts of chromium, which give them their characteristic red color.

Rubies are primarily found in metamorphic rocks, such as marble and schist, where the conditions for their formation involve high pressure and temperature. They can also occur in alluvial deposits, where they are carried by rivers and streams from their original source rocks.

Ruby mining involves exploration and extraction from primary deposits (in situ in rocks) or secondary deposits (alluvial deposits in rivers and streams). Techniques such as open-pit mining, tunneling, and dredging are used depending on the deposit type and location.

Once rubies are mined, they are sorted, cleaned, and cut to enhance their appearance and value. Skilled lapidaries shape and polish the stones to maximize their brilliance and color.