Abstract: This article is a brief survey of the historical methods of describing and assessing the quality of coloured gemstones, tracing these from ancient times to the end of the 18th century. Examining historical texts and inventories reveals how features and flaws of gemstones were observed and used to determine their value. This article considers various historical periods, including the ancient world, the medieval Muslim world, early India, and medieval Europe, highlighting the changing criteria and expertise involved in gem judgement. This study demonstrates the historical depth of gem connoisseurship and its influence on modern gem assessment practices.