A diamond and enamel Edward VII monogram brooch

the interlaced initials signifying Edward Imperator Rex (Emperor, King), with the E and I in red guilloche enamel, the R in white opaque enamel, all studded with rose cut diamonds, beneath a crown surmount with red and green enamel details, the back stamped '18' and tests for 18ct gold, length 3.6cm, in original fitted gold-tooled leather case by Collingwood (Qty: 1)

Footnote: King Edward VII and Queen Alexandra were regular clients of Collingwood & Co, buying many jewels there, especially gifts such as the present example, which were distributed at Christmas or on the occasion of a royal visit