Gemstone Briefs

Here’s what’s happening in Tanzania’s colored-stone sector:

  • Tanzanite production continues, but, with buyers increasing and supplies dwindling, much smaller quantities are available than before. As a consequence, prices for tanzanite rough have reached unprecedented highs. However, in the United States and elsewhere, tanzanite’s polished prices have not absorbed the higher prices for rough—yet. Finished goods in the upper three quality grades continue to hover around $300-$375 per carat.

  • Production of alexandrite and emerald has been spotty.

  • The Mahenge area has been producing beautiful spinel, both red and pink. It has also produced exceptional pieces of purple/blue spinel, which has been described as “not inky” and showing “great dispersion.” The bulk of the spinel has gone to Thailand.

  • The Kongwa area in the Dodoma region—previously known for its chrysoprase and scapolite—has been producing good quantities of moonstone.

  • Sapphire mining in the Umba Valley continues. Production is being processed and is expected to appear on the market shortly.

  • The almandine mines in the Umba Valley—which historically have produced the best quality in ample quantities—were recently purchased by a large-scale mining operation. More mining activity in the Umba area will mean greater quantities of tsavorite, rhodolite, and chrome tourmaline.