Beryl family: aquamarine, morganite, and emerald under one name

Aquamarine, morganite, and emerald are all the same mineral, beryl, colored by different trace elements, iron for aquamarine's blue, manganese for morganite's pink, and chromium or vanadium for emerald's green. Hardness runs about 7.5 to 8 across the group. Emerald is the outlier in durability despite the shared hardness number, because emerald crystals almost always contain internal fractures and inclusions (collectors and dealers commonly call this internal inclusion pattern the jardin, French for garden), and the great majority of emeralds on the market are treated with oil or resin to fill surface reaching fractures and improve clarity, a long standing and generally disclosed trade practice. Aquamarine and morganite are typically much cleaner and more durable in practice as a result.