Which one of the following gemstones contains beryllium metal?

Which one of the following gemstones contains beryllium metal?

Topaz
Emerald
Ruby
Blue sapphire
This question was previously asked in
UPSC CAPF – 2018
The correct answer is B) Emerald.
Emerald is a variety of the mineral beryl, with the chemical formula Be₃Al₂(SiO₃)₆. The chemical composition clearly shows the presence of Beryllium (Be) metal. The green color of emerald comes from trace amounts of chromium or vanadium within the crystal lattice.
Let’s look at the composition of the other gemstones:
– Topaz: Aluminium and fluorine silicate (Al₂SiO₄(F,OH)₂). Contains Aluminium, Silicon, Oxygen, Fluorine, Hydrogen.
– Ruby and Blue Sapphire: Both are varieties of the mineral corundum, which is aluminium oxide (Al₂O₃). Ruby is colored by chromium, and sapphire by iron and titanium.
Thus, out of the given options, only Emerald contains beryllium.