What is the most popular size of diamond stud earrings?

There is no definitive answer to this question as people's individual preferences can vary greatly. However, it is generally agreed that round-cut diamonds are the most popular type of diamond stud earring, followed by princess-cut diamonds. Other popular cuts include emerald-cut, oval-cut, and pear-cut diamonds. Ultimately, it is up to the individual to decide what size and style of diamond stud earrings best suit their needs and taste.