4.13 Ct. Cabochon Agate from Brazil

One beautiful translucent 4.13 carat oval shape brown agate is presented with precise measurements of 11.99 by 10.22 by 4.37 millimeters, a classic cabochon cut that emphasizes the stone natural color and internal character, the clarity grade is very slightly included when evaluated at eye level, the color intensity is medium intense, the polish has been assessed as excellent, no enhancement has been applied, and the origin is Brazil. This combination of weight size and color intensity places this specimen in an uncommon tier among commercially available agates, because it is unusual to find a cabochon cut agate of over four carats that retains translucency and a uniform medium intense brown without dye or other treatments. The oval cabochon shape has been selected to maximize the visual depth and evenness of tone, resulting in a warm luminous appearance that reads as rich amber brown under both natural and controlled lighting. The Natural Gemstone Company offers this stone as a rare natural example that will appeal to collectors and designers who prioritize untreated material and transparent provenance.

A discussion of grading and clarity helps explain why this piece is of interest to an educated buyer, clarity grading for agate and other chalcedony varieties differs from the system used for faceted transparent gemstones, the reported clarity of very slightly included at eye level means that under normal viewing conditions minor internal features are present but neither distracting nor structurally compromising, these features are consistent with natural agate formation and may include faint banding, thin growth lines, or minute mineral inclusions, such internal characteristics often contribute to the identity and value of the specimen rather than detract from it. When grading at magnification such as ten times, additional internal features may be visible and their presence should be expected in a natural stone of this size, however the absence of obvious surface reaching fractures and the excellent polish indicate that the cutter was able to achieve a durable and attractive finished gem. Color grading for chalcedony is best reported using descriptive terms for hue tone and saturation, here the primary hue is brown, the tone is medium which conveys a pleasing balance between light and depth, and the saturation is enough to be characterized as medium intense, a level of intensity that reads as both natural and versatile for jewelry applications.

The provenance of this agate is Brazil, a well documented source for quality chalcedony and agate nodules, Brazilian agates typically form within volcanic basalt cavities where silica rich fluids precipitate microcrystalline quartz over time, this geological context often yields stones with stable color and consistent translucency, and the country has a long history of producing material that is left untreated for collectors and designers. From a gemological perspective agate is a variety of chalcedony with a Mohs hardness around seven and a specific gravity generally near 2.60 to 2.64, these physical properties make it suitable for daily wear in most jewelry settings when properly set, the cabochon cut enhances resistance to chipping by eliminating pointed facets and by distributing impact forces across a curved surface. The dimensions of 11.99 by 10.22 by 4.37 millimeters combined with a weight of 4.13 carats indicate that the cutter preserved substantial material and achieved an optimal depth to display translucency, this proportional relationship between millimeters and carat weight is consistent with the expected density of chalcedony and supports the visual impression of a solid, substantial gem rather than a thin foil backed or assembled material.

For the educated buyer seeking rarity and value the attributes of this brown agate are significant, first it is unenhanced which is increasingly difficult to source in quality agates at this size, second the medium intense translucent brown color is comparatively rare among cabochons of similar carat weight which are often either too dark opaque or too pale, third the clarity described as very slightly included at eye level paired with an excellent polish makes it appealing for designs where the stone will be viewed closely, and fourth the documented Brazilian origin provides geological context and a track record for stable natural color. From the perspective of market positioning this stone is desirable for bespoke jewelry projects where a warm natural tone is required without reliance on treatments, and collectors will appreciate the combination of size rarity and natural state as part of a curated cabinet. The Natural Gemstone Company is committed to transparent description and responsible sourcing, and we present this specimen with full measurements photographic documentation and a clear statement of enhancement status. If you require additional technical information such as matching pairs potential cutting options or verification under specified lighting conditions please contact The Natural Gemstone Company for further details and assistance.