17.98 Ct. Bi Color Sapphire Crystal from Ceylon (Sri Lanka)

This 17.98 carat semi transparent bi color sapphire exemplifies a fusion of natural crystal habit and careful lapidary refinement, offered by The Natural Sapphire Company. The stone measures 24.02 x 9.98 x 8.76 mm and is executed in a rough crystal cut that preserves original termination planes and an elongated, various shape outline. Color zoning is pronounced, with a warm golden yellow body grading into a cool blue at one termination, yielding a distinct bi color effect with medium color intensity. Clarity is graded included at eye level, and internal features and mineral inclusions are observable without magnification, which contributes to the gem character and transparency reading. Polish is excellent across cut faces and finished surfaces, producing crisp surface reflections despite the retention of natural crystal geometry. No enhancement has been performed, confirming native color and structural features consistent with Ceylon origin, and the specimen carries the expected corundum hardness of nine on the Mohs scale and refractive index in the range typical for sapphire, which together support durable wear in a variety of settings.

From a technical and design perspective this sapphire offers unique opportunities and considerations. The rough crystal cut preserves asymmetrical facets and natural ridges that interact with incident light differently than conventional faceted stones, producing subdued but complex internal light distribution and subtle pleochroic shifts between yellow and blue viewing axes. The medium color intensity and semi transparent body respond well to open backed or partially open settings where light transmission enhances the bi color transition, and orientation of the stone to align the color boundary with the jewelry focal plane will maximize visual impact. Because inclusions are eye visible the stone is best suited to designs where the organic aesthetic is desirable, or for collectors who value unheated Ceylon material with documented provenance. The Natural Sapphire Company can provide full gemological documentation on request, and our lapidary team can advise on mounting strategies that preserve the crystal character while securing the stone for daily wear. This specimen represents a rare, untreated example of Sri Lankan sapphire morphology, combining geological authenticity with precise finishing and presentation.