13.05 Ct. Alexandrite from Tanzania

Deep below the earths surface, where heat and pressure remold continents and mineral rich fluids migrate through crystalline rocks, this alexandrite began its slow, patient life millions of years ago. Chromium bearing solutions infiltrated a beryllium rich host during regional metamorphism, and under those precise conditions the chrysoberyl lattice incorporated trace chromium atoms, creating the rare ability to change color with light. Over geological time frames, tectonic uplift and erosion revealed pockets of gem quality material, and skilled cutters transformed a rough crystal into the elegant 13.05 carat oval, with dimensions of 14.77 by 11.67 by 9.09 mm, that you see today. The mixed brilliant cut was chosen to maximize both the color change from yellowish green to reddish green and the internal fire, while an excellent polish allows light to travel and return with lively dispersion. This gem is transparent, very slightly included when evaluated at eye level, and shows a medium intense color, attributes that speak to its natural, unenhanced origin from Tanzania, and to the genuine geological story it carries.

Compared with other alexandrites and market options, this stone stands out for size, natural color change, and lack of enhancement, qualities that are increasingly rare among natural gemstones. Many alexandrites on the market are smaller, heavily included, or have been heat treated or irradiated to improve color, while this piece from The Natural Gemstone Company is offered intact and untreated, preserving both beauty and investment integrity. The clarity grade and excellent polish provide superior light performance compared with typical commercial material, and the mixed brilliant cut balances brilliance and color play in a way that most standard oval cuts do not. For collectors and connoisseurs seeking provenance, the Tanzanian origin adds a distinctive geological fingerprint, and for those choosing a wearable centerpiece, the generous 13.05 carat weight translates to presence and versatility in custom settings. In short, this alexandrite offers a rare combination of geological authenticity, visual drama, and long term value, making it a more compelling choice than many alternatives on the market.