Scientists suspected that if a meteorite smashed into Earth hard enough (as one did to make the crater pictured, right), it could change a type of soft, pure carbon into lonsdaleite
, a mineral harder than diamond.
In diamond presentations, Dr Thomas Hainschwang (GGTL Laboratories, Balzers, Liechtenstein) and co-authors examined unusual black diamonds containing inclusions of lonsdaleite
(the hexagonal polymorph of diamond) and CO2.
Not so much chalk and cheese as lonsdaleite
: a rare type of diamond, also called a hexagonal diamond, only found in non-terrestrial areas such as meteorite craters.
It is true that carbon-based materials such as diamond, lonsdaleite
, and graphite have been known to mankind for ages.
These carbon allotropes include lonsdaleite
(Frondel and Marvin 1967), buckminsterfullerene (Kroto et al.
Using computer simulations, researchers have found two minerals that beat diamond as nature's hardest substance: wurtzite boron nitride and lonsdaleite.
When wurtzite boron nitride and lonsdaleite are compressed, the bonds between atoms malting up the minerals' crystals change their orientation.
These nano-sized, hexagonal bits of diamond, called lonsdaleite
, can be good tracers for impacts; they're created in the intense pressure and heat of a space collision.
Before long, you'll have structure resembling diamond's tetrahedral lattice or the hexagonal structural motif of lonsdaleite
, another all-carbon mineral.
"The type of diamond we have found - Lonsdaleite
- is a shock-synthesized mineral defined by its hexagonal crystalline structure.
London, Feb 17 (ANI): A material known as lonsdaleite
has displaced diamond as the "world's hardest material".