0.43 Ct. Bi Color Sapphire from Montana

This transparent 0.43 carat oval sapphire from Montana carries a precise set of measurements and finishing attributes that will immediately interest a technically minded buyer, The Natural Sapphire Company presents this gem with exact dimensions of 5.46 x 3.70 x 2.50 mm, an oval outline chosen to balance weight retention and optical performance, a mixed brilliant cut executed to enhance scintillation, a clarity grade of very very slightly included evaluated at eye level, light color intensity in a bi color distribution, and an excellent polish. The mixed brilliant strategy employed here uses a brilliant faceted crown working in concert with a pavilion that combines modified brilliant and strategic step elements, producing a controlled return of light within the small table and shallow depth profile. In a gem of this 0.43 carat size the cutter prioritized facet geometry to maximize apparent spread and sparkle, adjusting crown angle and crown facet proportions to work with the stones modest depth, while maintaining symmetry and a clean girdle profile to ensure secure and precise setting options for fine jewellery. The heat treated enhancement applied to this sapphire is a standard, stable treatment, used to refine color uniformity and to reduce the visibility of very fine internal features, while preserving the natural zoning that gives the stone its bi color character.

The story of formation for this Montana sapphire begins deep within the Earth under conditions of high temperature and pressure, where aluminium rich environments allowed corundum to nucleate and grow over prolonged intervals, a process that took millions of years. Trace concentrations of iron and titanium, unevenly incorporated during growth, produced subtle variations in absorption across the crystal, resulting in the bi color zoning observable in the finished gem, a record of fluctuating chemistry during incremental crystal growth. Over geological time frames tectonic uplift and erosional processes exhumed the host rocks, and subsequent weathering liberated sapphire crystals into alluvial systems typical of Montana provenance, where mechanical abrasion rounded and smoothed outer surfaces while preserving internal growth features. The result is a crystal that combines structural integrity with a complex internal history, features that the cutter read and respected when planning the facet layout. The mixed brilliant strategy was specifically chosen to translate the internal color zoning into attractive face up color distribution, minimizing dead zones while accentuating the subtle interplay between the two hues present in this specimen.

From a craftsmanship perspective this sapphire demonstrates several deliberate technical choices that cater to discerning collectors and jewellers. The oval shape is proportioned to enhance optical spread given the 5.46 x 3.70 mm footprint, ensuring that when set the gem presents with proportional length to width balance, while the pavilion faceting follows a modified brilliant schema to control light leakage in a stone with a shallower profile of 2.50 mm. Clarity assessment at eye level as very very slightly included indicates that inclusions are minimal and do not detract from face up performance, allowing the cut and polish to dominate visual effect. The excellent polish reflects careful lapidary finishing, with facet junctions that align precisely and girdle surfaces that are consistent around the perimeter, an important detail for secure setting and for preserving the optical integrity of the stone under light. The light color intensity and bi color zoning make this sapphire versatile for custom settings, performing well in both yellow and white metal mountings where the subtle color interplay can be emphasized or contrasted by the choice of metal and setting style. As with all offerings from The Natural Sapphire Company, provenance, treatment disclosure, and measured parameters are provided to ensure transparency, and our lapidary team can advise on mounting and design options that respect the stones unique crystallographic history while maximizing visual performance.