"I was particularly interested in your comments about South Africa today, living in retirement just 50 miles South of Sodwana Bay in St.Lucia. One of the first things you notice walking along the beach is a black deposit most people would mistake for oil pollution, it is in fact Titanium oxide.

"Totally irrelevant from the point of view of high finance your readers might be interested to know that one of the reasons that Leatherback turtles use these sands to bury their eggs in, is that the Titanium in the sand helps to keep it at the correct temperature at night time for the eggs to develop, it acts as a storage heater. An amazing evolutionary adaptation."

Eoin Treacy's view Thank you for this interesting email. I witnessed the leatherbacks laying their eggs back in 2001; it's an amazing experience.