A BROOCH in the shape of a butterfly which dates from circa 1850, is being offered for sale at auction by O'Reilly's of Dublin next Tuesday from 1pm.

A fine example of early Victorian jewellery, set in silver and gold, the brooch's wings are set with rose-cut diamonds while the body features sapphires, rubies and demantoids.

Green in colour, demantoids are the most expensive and rare form of garnets ever since they were first discovered and mined in Russia's Ural Mountains around the same time the brooch being offered by O'Reilly's was made. The demantoid was much used in jewellery throughout Europe during the second half of the 19th century and featured in many pieces made by Russia's most famous jeweller of the period, Peter Carl Fabergé.

The brooch is estimated to sell for €4,800-€5,200. The same sale also includes other gems including a number of diamond solitaires, as well as pieces of Irish silver such as a teapot made in Dublin in 1820 and an 18th century cream jug.