THERE’S always something new out of Africa, complained the Roman Pliny the Elder, as did Aristotle before him. They didn’t approve of novelty. But even they might have been impressed with the latest geological sensation from the continent: the world’s biggest lump of tanzanite, found 270 metres below ground in a mine near Mount Kilimanjaro in Tanzania last month.
Tanzanite is the newest of the precious stones, and one of the most sought-after because of its rich lavender-blue-azure colour; blue gemstones are rare. Tanzanite is considered fifth in line after the “big four”: diamond, emerald, ruby and sapphire. Discovered in…
