By: US today

From the hills of Kenya and Tanzania emerge two of the continent's most extraordinary gemstones: Tanzanite and Tsavorite. Discovered in the late 1960s and early 1970s, these rare stones have become cornerstones for collectors, celebrated for their unique beauty and geological rarity.

Leading their promotion is The Rare Gemstone Company, a Nairobi-based firm that has operated for five decades. Founded by coffee farmer Basil Zagoritis after he identified sapphires in his fields, the company is now led by his son, Antony Zagoritis. The firm operates on a vertically integrated, mine-to-market model, focusing on the top one percent of gemstones and emphasizing integrity in sourcing, precision cutting, and verifiable provenance.

Tanzanite, found only in a small area near Mount Kilimanjaro, is renowned for its brilliant blue-violet hue and striking pleochroism. Tiffany & Co. once hailed it as the most exciting gemstone discovery in 2,000 years. With a hardness of 6.5 on the Mohs scale, it is considered a one-generation gem due to its limited deposits.

Tsavorite, a vibrant green garnet discovered near Kenya's Tsavo National Park, rivals emerald in color but offers greater durability with a hardness of 7 to 7.5. It is considered rarer than Tanzanite in sizes over two carats.

The company's approach combines artisanal cutting—aimed at maximizing a gem's natural color—with a strong emphasis on ethical practices. It has developed a digital provenance system that traces each stone from the mine to the market, providing buyers with verifiable authenticity. Furthermore, the company channels royalties back to mining communities to fund local development projects. This commitment to transparency, sustainability, and artistry has established the firm as a leader in the world of rare and ethically sourced gemstones.