Over the past several years, diamond simulants have entered the market that consisted of colorless cubic zirconia reportedly coated with a thin layer (e.g., represented to be 30–50 nm) of nanocrystalline diamond particles embedded in a matrix. One manufacturer, Serenity Technologies (Temecula, California), has marketed this material as Diamantine. SIMS chemical analysis of samples obtained from Serenity in October 2009 indicated a very thin (~5 nm) film of carbon (along with Al and Ti) on the CZ surface. Durability tests performed in conjunction with SEM imaging demonstrated that the thin coating does not completely withstand typical gemstone cleaning and handling procedures. The only standard gemological technique that could establish the presence of a coating was EDXRF spectroscopy, which detected Ti from the adhesion layer deposited on the CZ during the initial part of the coating process.