0.74 Ct. Blue Cobalt Spinel from Ceylon (Sri Lanka)

This 0.74 carat cushion shape blue cobalt spinel is an outstanding example of what discerning collectors seek, offered by The Natural Gemstone Company. It measures 5.52 by 4.68 by 3.41 millimeters, giving it a pleasing presence on the finger without overwhelming the setting. The gem is transparent, cut in a mixed brilliant style, which marries step cut pavilion facets with a brilliant style crown to maximize both durability and scintillation. The polish is rated excellent, producing crisp facet junctions and lively return of light that accentuates the stone's saturated hue. With a weight of 0.74 carat and this exact proportion, the gem sits comfortably within the sweet spot for collectors who are seeking rare color intensity and precision cutting in an intimate size that works well for rings, pendants, and bespoke jewelry pieces.

Color is the defining attribute of this cobalt spinel, described here with a true emphasis on accuracy, for the educated buyer. The tone is intense, with a cool deep blue that leans slightly towards a pure blue rather than violet or gray, a quality that is highly prized in cobalt bearing spinels. The blue in cobalt spinel is caused by the presence of divalent cobalt ions, a chromophore that produces vivid saturation at relatively low concentrations, creating colors that rival fine blue sapphires yet remain distinct in hue and optical behavior. Spinel is a single refractive, isotropic gem with refractive indices that typically range from 1.718 to 1.762, and a Mohs hardness of 8, which gives it strong resistance to daily wear while allowing exacting cuts to be executed. The absence of treatments, confirmed as no enhancement, enhances its appeal to collectors who prioritize natural state gems, and the origin from Ceylon, Sri Lanka, adds a historical provenance that many connoisseurs value.

Clarity and cut quality are central to assessing the long term appeal and market value of this stone. The clarity grade is very slightly included when evaluated at eye level, a practical and honest assessment that indicates small inclusions are present but do not detract from overall transparency or brilliance when mounted. These inclusions are typical of natural spinel and often manifest as pinpoint crystals or minute feathering that are stable and eye clean to most observers. The mixed brilliant cut optimizes light performance, with a crown and table arrangement that produces both sparkle and depth, and the pavilion faceting engineered to enhance face up color without creating dead zones. For settings, this gem is ideally suited to four or six prong designs that protect the corners of the cushion shape while showcasing the table area. Collectors and jewelers should appreciate that the excellent polish and precise facet symmetry allow the stone to display maximum color saturation and scintillation under natural and artificial light alike.

Provenance, rarity, and presentation complete the story that makes this blue cobalt spinel a perfect addition to a high end gemstone collection. Ceylon, Sri Lanka, has a long and respected history for producing high quality spinels and sapphires, and stones from this source command attention for their natural color and trustworthy supply chain when sourced responsibly. The fact that this gem is untreated elevates its appeal in specialist markets, where natural state, provenance, and gemological clarity command premiums. From an investment and collecting perspective, cobalt spinels are increasingly sought after for their combination of vivid color, relative scarcity compared with other blue gemstones, and excellent wearability. At The Natural Gemstone Company we present this gem with full disclosure of its grading characteristics, with practical advice on mounting and preservation, and with the expectation that it will be treasured by collectors who value true natural color, skilled cutting, and verified origin. For anyone building a considered, scholarly, and aesthetically outstanding collection, this 0.74 carat cushion cobalt spinel from Ceylon represents a rare opportunity to secure a vibrant, untreated, and well fashioned gem that excels both as a wearable jewel and as a portfolio quality specimen.