The crossword solution for the term 'Mounts, as a gem' is SETS. This term refers to the process of setting a gemstone into a piece of jewelry. This is done by using a metal setting to secure the gemstone in place. The metal setting is usually made of gold, silver, or platinum and is designed to hold the gemstone securely while also allowing it to be displayed. Setting a gemstone is an important part of creating jewelry, as it ensures that the gemstone is secure and will not fall out.