0.69 Ct. Cobalt Spinel from Ceylon (Sri Lanka)

This listing features a single, transparent cobalt spinel weighing 0.69 carat, presented in a classical round shape, with precise dimensions of 5.28 x 5.37 x 3.45 mm. The stone has been fashioned in a mixed brilliant cut to balance scintillation and depth, and it displays an intense, richly saturated blue that is characteristic of cobalt bearing spinel material. Clarity has been evaluated at eye level as very slightly included, a grade that denotes minor internal features that do not detract from the gem when viewed without magnification. The polish on all facets is excellent, contributing to crisp facet junctions and lively return of light, and importantly, this spinel has not undergone any enhancement, a natural state that is highly prized by informed buyers. Origin is documented as Ceylon, Sri Lanka, and the provenance is a significant part of this gem story offered by The Natural Gemstone Company.

When assessing a gem of this nature, the combined attributes of cut, clarity, color, and polish inform both aesthetic appeal and market value. The mixed brilliant cut used here is chosen to maximize face up brilliance while retaining good depth to preserve the stone weight without appearing shallow. With the very slightly included clarity grade, the stone presents a clean appearance to the unaided eye, which is the practical benchmark for wearable gems. The excellent polish reduces light leakage at facet junctions and enhances luster, which can be particularly important in darker blue tones where surface finish influences perceived saturation. The dimensions 5.28 x 5.37 mm place this stone in a size range that is ideal for solitaire rings and delicate pendants, where proportion and table size create a pleasing balance on the finger or neck.

From a gemological perspective, cobalt spinel deserves attention for both its chemistry and its optical behavior. Spinel has a robust hardness of approximately 8 on the Mohs scale, making it well suited to everyday wear in rings and other jewelry that encounter routine contact. The vivid blue color in cobalt spinel is caused by trace amounts of cobalt substituting into the spinel structure, producing hues that can rival traditional blue gemstones while remaining distinct in their tone and saturation. Unlike some other blue gems that may show pleochroism or strong birefringence, spinel is singly refractive and typically displays uniform color from different viewing angles, which contributes to the even, intense visual impression of this piece. The untreated condition of this gem means the color and clarity are natural, an important factor for collectors and connoisseurs who prioritize authenticity.

The origin of a gemstone can materially affect both desirability and value, and Ceylon, Sri Lanka is a storied locality with a long reputation for producing some of the world s finest gems. Sri Lankan geology includes metamorphic terrains and gem gravels that have yielded high quality corundum and spinel for centuries, and gems from this region are associated with refined color character and clean crystal habits. For the educated buyer, provenance from Ceylon often conveys a premium because of the region s documented history in the gem trade, established cutting traditions, and known mineralogical signatures. Additionally, responsibly sourced Sri Lankan gems often come with a transparency in the supply chain that many buyers expect today, and The Natural Gemstone Company places emphasis on traceable sourcing and proper documentation, enhancing confidence in the gem s background.

For an informed purchaser or collector, this 0.69 carat Ceylon cobalt spinel represents an attractive convergence of natural color, wearable durability, and unenhanced provenance. It is well suited for a refined solitaire setting that emphasizes the jewel s intense blue face up appearance, and the mixed brilliant cut will translate into lively scintillation in both natural and artificial light. We advise consideration of independent gemological reporting when assigning long term value, and a standard report will confirm origin, treatment status, and measured properties to complement the visual assessment. As part of our inventory at The Natural Gemstone Company this spinel is presented with full disclosure of its characteristics, and for buyers who value unenhanced natural color, clear eye level clarity, and the historical cachet of Ceylon provenance, this stone offers a compelling proposition.