Identify this mineral whose varieties include aquamarine and emerald, the namesake of element number four.
This mineral comes in several varieties including goshenite, heliodor, and bixbite, the last of which is also known as "red emerald". The blue variety of this silicate is named for sea water, though the green variety is the most sought- after and expensive. While some varieties are used as gemstones, in general, the mineral is best-known as the source of its namesake rare element. Identify this mineral whose varieties include aquamarine and emerald, the namesake of element number four.
This mineral comes in several varieties including goshenite, heliodor, and bixbite, the last of which is also known as "red emerald".
{beryl} [do not accept variations such as “beryite” or “beryllium”]