Indeed, "artificial diamond" is one of the top examples of the first definition of "artificial" at Merriam-Webster, which is "man-made." [1] Etymologically it

Indeed, "artificial diamond" is one of the top examples of the first definition of "artificial" at Merriam-Webster, which is "man-made." [1] Etymologically it means "made by skill." But I understand the hesitation to use the word, as it gives an impression of "fake." https://www.merriam-webster.com/dictionary/artificial https://www.merriam-webster.com/dictionary/artificial