Beryl,

frequently occurring mineral from the mineral class of silicates and germanates. Structurally it belongs to the ring silicates. In its pure form, beryl is colorless and transparent and is called "goshenite". By foreign admixtures it can show different colors. Well-known varieties are the blue aquamarine, the green emerald, the yellow golden beryl, the greenish-yellow heliodor, the pink morganite and the red bixbit.