Composition and Characteristics
The name ‘emerald’ was not used in England until the 16th century and has its roots in Latin, ‘smaragdus’, and the later mediaeval; ‘esmerande’, ‘emerande’ and ‘esmeralde’. All of these names refer to the deep green colour of the stone.
An emerald is a member of a range of stones called Beryl (Be3Al2 (SiO3)6) by mineralogist. The colour spectrum for Beryl is broad and includes Aquamarines in shades of blue-grey, morganite in pink and yellow heliodor. The purest form of Beryllium is colourless. The rich green colour characteristic of emerald is created by the presence of other mineral deposits within the stone, such as traces of chromium or, less frequently, vanadium. Although, these additional minerals are technically impurities in the beryllium, they create the bright colours that make the stones so attractive and valuable.