Swiss Diamond

Swiss Diamond cookware has a patented, nonstick surface consisting of real diamond crystals that won’t crack or peel, according to the company. The hardness of the crystals creates a nonstick surface that Swiss Diamond claims is nearly indestructible. Some reviewers refer to gemstones when describing Swiss Diamond's nonstick cookware, though the company does not use the term itself.

Nordic Ware

Some online advertisements refer to Nordic Ware’s microwave cookware as a gemstone product. A Cooking.com ad for the cookware describes gemstone as a special polymer that's exclusive to Nordic Ware. Other ads describe Nordic Ware's gemstone as an unbreakable plastic material that’s also chip-proof and easy to clean. However, Nordic Ware doesn’t mention the gemstone material in the description of its microwave cookware on its website.

BPA

Some items that merchants market as gemstone cookware may contain fewer chemicals than similar products. For instance, Nordic Ware indicates that its microwave cookware is BPA-free. The U.S. Food and Drug Administration (FDA) has raised concerns about the potential health effects of BPA, or bisphenol A, contained in plastic cookware and bottles. The BPA absorbed by food, for example, could increase gland disorders and behavior problems among infants and young children, according to the FDA.

PFOA

Perfluorooctanoic acid (PFOA) is often used to make the polytetrafluoroethylene (PTFE) that creates nonstick surfaces on any type of cookware. There's an ongoing debate among consumer groups, manufacturers and others about whether PFOA presents health risks. However, Swiss Diamond asserts that adding diamond crystals to its nonstick cookware surfaces requires high temperatures that eliminate PFOA. In any case, the company notes on its website that it has been using PTFE made without PFOA since 2008.