This is the number one question I have been ask over my years in the jewelry business.
The majority of people do not know what to look for to determine if a stone is a cz, diamond, or other diamond simulant.
Flawless and colorless diamonds are expensive and become more expensive the larger you go. All Cubic zirconia are colorless and flawless. Keep that in mind if you want to pass your stone as real. For example, I wear 2ctw Russian CZ stud earrings daily, and my friends think they are real even at a closer look. They think that because they know I work in the jewelry industry and assume I got them at an extreme discount. They also know if I wasn’t in the jewelry industry I probably would not be able to afford 2-1ct colorless and flawless stones.