Emerald is a variety of the silicate mineral beryl, which crystallizes in the hexagonal crystal system and has a Mohs hardness of 7.5 to 8. Its chemistry is described by the composition Al2Be3[Si6O18]. The color is green due to the addition of chromium and vanadium ions, the line color is white.

Etymology and history

The word "emerald" comes from the Latin smaragdus and from the Greek σμάραγδος, smáragdos (green stone); it is also related to Sanskrit marakatam (green); however, the word is probably of Semitic origin, cf. Akkadian barraqtu "sparkling stone", to the root BRQ "sparkle" and Hebrew ברקת (bāreqet), "emerald" to ברק (bâraq), "flash".

Emerald mining began in ancient Egypt. The precious stones were mined there as early as the 13th century BC; for more than a thousand years, Sikait and Sabara (mines) supplied Europe with the precious minerals. The stones were also in great demand in the Orient among the Persians, Ottomans and the Mughal rulers of India. When the Spaniards conquered South America in the 16th century, they also encountered a lively trade in the stones there, which extended from Colombia as far as Chile and Mexico. The Muzo mine, which they conquered in 1573, replaced the Egyptian sources from then on. Today, 55 percent of all emeralds worldwide come from Colombia.

In 1935, I.G. Farben in Bitterfeld was the first to succeed in producing synthetic emeralds of polishable quality.