1.37 Ct. Bluish Green Sapphire from Montana

This exquisitely transparent 1.37 carat round bluish green sapphire measures 6.62 by 6.58 by 4.38 millimeters, a near exact round that reflects careful preforming prior to faceting, and it showcases the technical hallmarks collectors seek. The gemstone is faceted in a mixed brilliant cutting style, combining a brilliant crown with a precisely faceted pavilion to balance scintillation and color depth. Clarity is graded very very slightly included at the eye level, delivering an appearance that is effectively eye clean while retaining internal characteristics that confirm natural formation. Color intensity is classified as intense, and the surface exhibits an excellent polish that produces crisp facet junctions and high surface luster. The sapphire has undergone a standard and stable heat treatment to optimize hue and reduce silk, and its origin is Montana, a source renowned for vivid teal and bluish green material with an appealing earth derived character. The Natural Sapphire Company stands behind the gem provenance and cutting specifications, offering transparent technical detail for informed buyers.

The mixed brilliant faceting applied here is engineered to leverage the sapphire’s higher refractive index, with the sapphire’s refractive index range approximately 1.762 to 1.770 contributing to strong light return and focused brilliance. The round outline is executed with a controlled crown geometry and a pavilion designed to channel light back through the table, and the result is a balance between fire and saturation that accentuates the bluish green tone. The measured depth of 4.38 millimeters corresponds to approximately 66.4 percent of the average diameter of 6.60 millimeters, a proportion that favors color saturation without sacrificing live brilliance. The mixed brilliant approach uses a brilliant facet pattern on the crown to maximize scintillation, while the pavilion facet architecture refines the internal light paths so color is seen uniformly across the face up presentation. Excellent polish ensures minimal light diffusion at facet junctions, producing clean flashes and a lively face up presence under mixed lighting.

Color technically defines this stone and determines how it will perform in jewelry. The intense bluish green hue displays pleochroic behavior typical of corundum, exhibiting more pronounced blue or green tones when viewed from different crystallographic orientations, and the mixed brilliant cut mitigates apparent color zoning by distributing light and integrating tonal shifts. In practical terms this means the gem will project a saturated, lively color whether set in a solitaire ring, halo pendant, or stud earrings. Metal choice will further influence perception, with yellow and rose gold subtly warming and emphasizing greenish tendencies, while white gold and platinum emphasize the blue component and provide a modern, high contrast setting. An open pavilion or traditional prong setting enhances transmitted light and maximizes the stone’s brilliance and color saturation, while a secure bezel offers a contemporary aesthetic at the expense of some face up brightness. For customers seeking maximum visual impact, a halo of well calibrated smaller white diamonds will increase perceived size and create contrast, drawing the eye to the sapphire’s intense bluish green core.

From a clarity and durability perspective this Montana sapphire combines collector grade appearance with practical wearability. Very very slightly included material evaluated at eye level indicates that inclusions are minimal, localized, and do not detract from face up beauty, and the heat treatment applied is a stable, industry accepted enhancement that improves hue and transparency without compromising structural integrity. The specific gravity of corundum around 4.00 and the precise cutting proportions result in a stone that sits comfortably in fine jewelry, offering secure mounting options and daily wear resilience. At The Natural Sapphire Company we document cutting style, measurements, clarity grade, treatment status, and origin so clients can make informed decisions when commissioning settings or designing bespoke pieces. This 1.37 carat round bluish green sapphire will stand out in any jewelry setting, delivering an intense, lively color performance, precise facet craftsmanship, and the robust provenance that discerning buyers appreciate.