4.09 Ct. Green Sapphire from Tanzania

This listing describes one transparent green sapphire from The Natural Sapphire Company, weighing 4.09 carat, cut into a round shape with a mixed brilliant cut. The gem measures 8.72 by 8.70 by 6.85 millimeters, yielding an approximate depth of 79 percent relative to its average diameter. Clarity is graded as very slightly included, evaluated at eye level, indicating most internal features are subtle and do not detract from overall transparency. Color intensity is described as intense, and the stone has received an excellent polish. The sapphire is natural, with no enhancement, and its documented origin is Tanzania.

The mixed brilliant cut has been executed to balance face up brilliance with depth of body color, the crown facets delivering lively scintillation while the pavilion facets maintain strong color saturation. The excellent polish produces crisp facet junctions and clean facet surfaces, which enhance both brilliance and scintillation. The very slightly included clarity grade means that, when viewed without magnification, the stone reads as transparent and clean, while a loupe will reveal minor pinpoint inclusions and faint internal silk that are typical for natural sapphires and contribute to character rather than distraction. The combination of precise cutting and high polish ensures that light is returned efficiently, maximizing perceived brightness while preserving the intense green that defines this piece.

Under a range of lighting conditions this sapphire presents a nuanced and attractive range of appearances, owing to its color saturation and cut. In bright natural daylight, particularly midday north light, the stone exhibits lively reflections and a balance between deep forest green and lighter grassy undertones around facet edges, the mixed brilliant cut producing crisp white flashes and green flashes in alternating motion. In direct sunlight the stone tends to show greater contrast, with bright scintillation from the crown facets and deeper, almost velvety green tones within the table and pavilion. Under warm incandescent or candlelight the green shifts toward a warmer, richer emerald tone, the sapphire appearing deeper and more saturated as the yellow component of the light enhances the stone body color. Under modern cool white LED or fluorescent lighting the gem can take on slightly bluer green highlights, the cooler spectrum emphasizing the blue component of the green and producing brisker, cooler flashes. In low ambient light the stone reads darker and more somber, with its intense color giving the impression of a deep bottle green, while under focused spot lighting or gallery lights the facet pattern comes alive with strong scintillation and play between dark and bright facets.

This stone is well suited to a variety of fine jewelry applications where both color and durability are priorities. As corundum, sapphire rates nine on the Mohs scale, providing excellent wear resistance for daily wear rings, pendants, or cufflinks. Given the stone depth near 79 percent, setting considerations are practical. A secure prong setting with a well-shaped seat will protect the girdle, while a bezel or partial bezel offers additional protection and can modulate perceived depth and table appearance. A halo or pavé surround will increase apparent size and add contrast to the intense green, while a simple solitaire presentation emphasizes the gem itself and its mixed brilliant facet play. The unenhanced Tanzanian origin and natural character make this specimen of particular interest to collectors and connoisseurs who prioritize untreated gemstones. At The Natural Sapphire Company we can provide additional high resolution images and videos under daylight and incandescent conditions to assist with selection, and guidance on mounting and care to ensure the stone performs as described for years to come.