In plain words, a diamond simulant, also known as simulated diamond, fake diamond, faux diamond, diamond imitation and diamond alternative, is a stone that looks similar to a real diamond. They are used in jewellery to imitate diamonds, however, they have completely different chemical structure. Some diamond imitations occur naturally, while others are created artificially in labs. Among the most popular simulants are cubic zirconia, zircon, moissanite, spinel and white sapphire.