Sapphires have been treasured for millennia, and deposits in Sri Lanka, Burma (Myanmar) and Kashmir are usually thought of as the most famous deposits. However, another deposit, in Yogo Gulch in Montana, USA, caused a considerable stir at the end of the 19th century, yielding superb and distinctive sapphires of its own. The deposits had been discovered as early as the 1860s, as a byproduct of the ‘gold rush’ that swept the region, but yields were small and went virtually unnoticed as the prospectors focussed their attentions solely on gold. In 1895, the prospector Ed ‘Sapphire’ Collins started to wonder if these small blue stones might actually be worth something. He sent a parcel to Tiffany’s famous pioneering gemologist, George Frederick Kunz, who promptly purchased the lot, declaring that they were ‘sapphires of unusual quality’. With this endorsement, a new sapphire rush began, and Montana sapphires suddenly shot to fame. Montana sapphires are set apart from other sapphires primarily by their range of attractive colours, the most famous of which is demonstrated here: an unusual, striking greenish-blue, not found in other sapphires. They also tend to be of more even colour than other sapphires, which are prone to patchy colour ‘zoning’ within the stone. These qualities combined to create gems of surpassing charm, and with Kunz’s endorsement they captured the imagination of Tiffany & Co., who championed them in their all-American jewels of the early 20th century. Montana sapphires also tend to be very small, and are most commonly below 1 carat, which means that this 2.40 carat blue-green gem is something of a rarity. Set in a simple cluster of circular-cut diamonds to a yellow gold band, this is a sapphire and diamond cluster with a story to tell.