Emeralds are a variety of the mineral beryl. Pure beryl is colourless but minute traces of chromium cause the rich green of emeralds. Flawless emeralds are extremely rare. Many are fractured and most contain mineral inclusions which help us distinguish natural gems from synthetic ones.
This ring forms part of a collection of 154 gems bequeathed to the V&A by the Reverend Chauncy Hare Townshend, a cleric and poet. Sir A. H. Church gave additional specimens in 1913. He also compiled the first catalogue Precious Stones: A Guide to the Townshend Collection. The first edition appeared in 1883. The stones are mounted as rings, although they may not have been intended to be worn.