0.67 Ct. Alexandrite from Ceylon (Sri Lanka)

This 0.67 carat cushion shape alexandrite offered by The Natural Gemstone Company exemplifies the qualities that knowledgeable gem buyers seek in a color change stone, from its verified origin in Ceylon, Sri Lanka, to its uncompromised natural state. Measuring 5.80 by 4.88 by 2.96 millimeters, this gem has been faceted in a mixed brilliant cutting style, combining the scintillation of a brilliant crown with the controlled light performance of a pavilion tailored to a cushion outline. The cutting proportions yield an attractive face up appearance, with a depth around 55 percent, which balances sparkle with spread to make the stone appear larger than its weight might otherwise suggest. The polish is excellent, delivering mirror like facet junctions that allow light to enter and exit the stone with minimal loss. The clarity grade is eye clean at typical viewing distances, meaning the gem shows no inclusions to the unaided eye, a characteristic that materially increases visual appeal and market desirability for collectors who prefer clean stones without needing magnification.

As a chrysoberyl mineral specimen exhibiting true alexandrite color change, the optical behavior of this gem is a primary source of its value and fascination. Alexandrite owes its dramatic shift in hue to chromium substitution within the crystal lattice, which creates selective absorption bands. Under fluorescent or daylight balanced lighting the stone reads as a greenish tone, while under incandescent or warm lighting the same material shifts toward an orangish tone, a phenomenon that remains the hallmark of alexandrite and differentiates it from many other gemstones. The color intensity of this particular stone is classified as light, which for discerning buyers provides a subtle and sophisticated palette that can be appreciated closely and in a variety of settings. The natural, untreated status of the stone is especially important, treatments can artificially alter color or clarity, and the absence of enhancement preserves both the gemological integrity and long term value of this alexandrite.

The structural and physical characteristics of alexandrite contribute directly to the remarkable sparkle and unique visual character of this gem. Chrysoberyl crystallizes in the orthorhombic system, a rigid lattice that, combined with a relatively high refractive index in the range of about 1.74 to 1.76, promotes strong light refraction at facet junctions. Even though dispersion in chrysoberyl is modest compared to gemstones like diamond, the interplay of high refractivity and expertly oriented facets in a mixed brilliant cut produces pronounced brilliance and crisp scintillation. In practical terms, the brilliant facets on the crown catch and reflect light back toward the viewer, while the pavilion facets direct light internally to enhance both brightness and the visibility of the color change. The well executed facet alignment and excellent polish of this stone maximize internal light return, creating flashes of light and shifting color that are immediate and engaging, qualities that set a finely cut alexandrite apart from stones with similar chemistry but inferior cutting quality.

For educated buyers, origin, treatment status, and optical performance inform both emotional and investment appeal. Ceylon, Sri Lanka has a long history of producing gemstones with attractive tones and clarity, and alexandrite from this region is prized for its natural color range and pleasing lightness. This piece, with its light color intensity and natural color change, is well suited for collectors and designers who value gems that perform well in everyday lighting conditions, and who prefer an authentic, untreated specimen. The eye clean clarity grade means that the gem presents a clean visual field to appreciate the color play without the distraction of visible inclusions, while the cushion shape offers a versatile setting profile favored in both classic and contemporary jewelry. The fact that the stone has not undergone heating or other enhancements ensures that its aesthetic and physical properties are stable and predictable, an important consideration for those who seek gems that will retain their character over decades.

When considering why this alexandrite is a meaningful acquisition, focus on the synergy of origin, cut, clarity, and natural color change, all authenticated by The Natural Gemstone Company. The gem combines the durability of chrysoberyl, hardness of about 8.5 on the Mohs scale, and a dense crystalline structure, with expert cutting that accentuates optical effects rather than merely maximizing weight retention. Buyers who understand the science behind alexandrite recognize that unmatched sparkle is not solely a function of dispersion but of facet architecture, refractive index, and the stone s ability to display different colors under different light sources. This Ceylon alexandrite, 0.67 carat, cushion shape, mixed brilliant cut, eye clean, excellent polish, no enhancement, presents a rare and honest example of the variety s charm, making it an excellent choice for collectors and designers who value authenticity, lasting beauty, and the captivating phenomenon of color change.