10-01. Rutile #1.
Rutile, strange and mysterious as an African mask.It will be the mineral of week #40 of this short tour of the geometry of Nature. Rutile can be found on the African continent from Sierra Leone to South Africa as well as in Europe Australia and America. Rutile has among the highest refractive indices of any known crystal. What makes it unique is that it often develops in other crystals and make them more valuable in the process creating asterism or cat eye like effect in sapphire, topaz, and rubies.
Considering its size and shape, its structure is quite complex – a tetragonal unit cell where the titanium cations have a coordination number of 6 and are surrounded by an octahedron of 6 oxygen atoms. Maybe that’s what guided me to do the background of this visualization as a pattern of a rutile’s binding between its various atoms. Impressive and inspiring symmetry! The central object itself is a recursive progression of a rutile unit cell polyhedra & atoms.
One last thing about this mineral, nano-size rutile particles are used in sunscreen lotions and because of their optical properties are very effective at absorbing the sun UV radiation. Summer is gone in one part of the world but it’s just starting in another!