6.99 Ct. Purple Amethyst from Ceylon (Sri Lanka)

This transparent cushion shape amethyst weighs 6.99 carats, and measures 15.66 by 10.38 by 6.66 millimeters. It is cut in a mixed brilliant style, and presents an intense purple hue with excellent polish. Under normal viewing conditions the clarity is evaluated as very very slightly included at eye level, effectively eye clean and free of visible interference to light passage. The stone is natural and untreated, with no enhancement, and its origin is Ceylon Sri Lanka. The proportions yield a balanced appearance on the finger and in a pendant, with a measured depth that supports strong light return while preserving the jewel s vivid color. The Natural Gemstone Company presents this specimen as a representative example of precision cutting applied to a fine Sri Lankan amethyst.

At the material level this amethyst is quartz, a trigonal crystal of silicon dioxide, with a refractive index in the range expected for quartz and a low but measurable birefringence. The presence of trace iron and the particular state of irradiation within the crystal produces the purple color that defines amethyst, and the crystal s transparency permits efficient internal transmission of light. Because quartz is uniaxial, light behaves in a predictable manner as it passes through the gem, and the relatively modest dispersion compared with higher index gems is compensated by the stone s clarity and intense coloration. The gem s Mohs hardness is approximately seven, which contributes to its durability in everyday wear while the internal structure lacks prominent cleavage that might otherwise interrupt optical pathways. The result is a material substrate that, when properly faceted, yields bright, controlled flashes and sustained brilliance.

The mixed brilliant cut employed for this cushion shape combines a brilliant facet arrangement on the crown with complementary facets on the pavilion that are influenced by traditional step cutting geometry. This hybrid approach increases the number of facet junctions that intercept incoming light, producing scintillation that appears as distinct, lively flashes as the piece or the observer moves. Precision in facet angles and symmetry is crucial because quartz has a lower refractive index than many gemstones, and therefore requires careful optimization of pavilion depth and crown angles to maximize total internal reflection rather than permitting light to leak through the pavilion. In this stone the cutters achieved a depth ratio that supports efficient light return while avoiding an over deep or shallow appearance. The excellent polish on each facet eliminates surface scattering, allowing unimpeded reflection and refraction, and the minimal inclusions ensure that light is not diffused internally. Together the facet design and surface finish create a dynamic interplay between brilliance and color, so that the amethyst displays both saturated violet body color and active white light flashes.

When considered as a finished gem the cumulative effect of material properties and cutting execution produces a type of sparkle that is notable even among colored gemstones. The intense yet transparent purple color reinforces the visibility of facet reflections, while the mixed brilliant geometry multiplies points of light and contrast. The eye clean clarity grade and pristine polish allow those reflections to remain crisp and well defined, producing scintillation that reads as immediate and lively at arm s length, and as sustained and complex under closer inspection. The absence of enhancement preserves the natural zoning and color saturation that collectors and makers value, and the Sri Lankan origin is consistent with the characteristic tone and saturation seen in high quality amethyst from that region. For jewelers and connoisseurs seeking a substantial cushion amethyst with measured optical performance, this 6.99 carat stone offers a reliable combination of intense color, precise cutting, and strong light performance. The Natural Gemstone Company provides this description to support informed selection and to document the technical attributes that produce the gem s distinctive sparkle.