Netopen Raw Diamond Rough Crystal Specimen 2.8ct — Natural Cognac Brown

The Netopen Natural Cognac Brown Raw Diamond Rough Crystal Specimen at 2.8 carats presents the deep, warm reddish-brown color that the international diamond trade markets as cognac — a color that arises from a fundamentally different physical mechanism than the nitrogen-driven yellow and champagne colors: natural plastic deformation of the crystal lattice during the diamond’s geological history, where extreme tectonic pressure applied at specific orientations to the growing crystal introduces structural irregularities in the carbon bond network that create graining planes visible in transmitted polarized light and produce selective absorption of the blue-green spectral range, resulting in the characteristic warm brown that deepens in intensity with greater deformation severity. This color mechanism is of significant scientific interest because it records the tectonic history of the geological environment in which the diamond formed and traveled — essentially making the brown color a record of geological events billions of years old preserved within the crystal itself. Netopen’s gemological assessment has confirmed through advanced spectroscopic examination that this cognac color is entirely the result of natural plastic deformation and has not been artificially introduced through irradiation, HPHT treatment, or surface coating. The crystal habit is primarily dodecahedral — the twelve-face curved form that develops when diamonds experience more dissolution during their mantle residence than the octahedral form — creating the rounded, slightly bulging outline characteristic of naturally worn rough crystals from river-deposited alluvial sources where additional mechanical and chemical transport has further modified the original crystal shape. Surface features include natural curved dissolution surfaces, minor surface pitting, and the characteristic adamantine luster of unpolished diamond. Dimensions approximately 7.8mm x 7.4mm x 6.9mm. Supplied in Netopen presentation box with full gemological documentation and color origin scientific explanation.