0.50 Ct. Bluish Green Cabochon Sapphire from Montana

This stone is a semi-translucent, pear-shaped bluish green sapphire weighing 0.50 carat, presented as a cabochon with dimensions of 6.15 x 3.89 x 2.01 millimeters. The geometry is a classic pear profile with a smooth domed surface and a discreetly proportioned pavilion, optimized for light diffusion rather than facet-driven brilliance. Clarity is graded slightly included at eye level, indicating the presence of small internal features that are visible without magnification but do not materially compromise structural integrity. Color intensity is described as light, consistent with Montana provenance, yielding a delicate bluish green that reads pastel under standard daylight. The material has been heat treated to stabilize and enhance the hue, a well-established and stable enhancement for corundum, and the cabochon has been finished to an excellent polish, producing a clean, even luster across the dome while preserving subtle internal character.

From a lapidary and gemological perspective, the decision to present this sapphire as a cabochon responds directly to its semi-translucent body and internal structure. Cabochon cutting maximizes the perception of color across the full surface area and allows color zoning, clouding, and internal growth patterns to contribute positively to the gem’s aesthetic, rather than being masked by facets. The dome height, relative to the 6.15 by 3.89 millimeter plan dimensions and 2.01 millimeter thickness, has been kept moderate to balance saturation with light transmission, producing a soft, diffused color that changes subtly with viewing angle. Corundum’s refractive index in this composition falls in the expected range for sapphire, and the material’s Mohs hardness of 9 ensures excellent wearing durability for jewelry applications, provided standard care is observed. The slightly included designation suggests typical Montana-type inclusions such as fine rutile needles, growth feathers, or tiny crystals, which contribute to the stone’s character without indicating structural weakness.

Practical considerations for setting, care, and valuation are straightforward. The cabochon profile and measured thickness make this 0.50 carat pear an ideal candidate for bezel settings, secure prong bezels, or custom mounting that orients the tapered point to accentuate directional color. Given the light intensity and semi-translucent nature, mounting that allows some backlight, or a lightly reflective backplate, will enhance apparent color. Heat treatment is common, stable, and accepted in trade, and should be disclosed, as is done here. Cleaning is best accomplished with warm water, mild detergent, and a soft brush, avoiding aggressive ultrasonic or steam cleaning only if surface-reaching fractures are suspected; routine gentle methods preserve polish and minimize risk. The combination of Montana origin, cabochon cut, and the stone’s delicate bluish green tone makes it attractive to connoisseurs who appreciate natural character and lapidary skill. For further information on this specific piece, including certification options and mounting recommendations, please contact The Natural Sapphire Company, where our team can provide detailed measurements, high-resolution imagery, and guidance on settings that will best showcase this pear-shaped Montana sapphire.