It is important to note the major distinction between lab diamonds and diamond simulants. Diamond simulants, such as cubic zirconia, look similar to diamonds but are not true carbon crystals. Simulants do not have the same chemical and physical properties as natural diamonds and therefore sell at much lower prices than man made diamonds. Simulants can be distinguished from natural or lab grown diamonds using only the naked eye.
Natural and lab grown diamonds have thermal conductivity properties that differentiate them from cubic zirconia with a handheld diamond tester. Some lab diamonds, along with some natural colored diamonds, may be mistakenly identified as moissanites when using certain diamond testers due to similarity in their electrical conductivity. However, gemologists can typically distinguish between diamond and moissanite due to their differing refractive properties, with moissanites being double refractive and diamonds being single refractive.