More from The National:
Friday's best photos: From a presidential resignation to a Moon landing
Thursday's best photos: From F1 testing to beekeepers protesting
Wednesday's best photos: From temple steps to an elephant crossing the road
Tuesday's best photos: From cleaning the statue of David to Olympic preparations in Tahiti
Monday's best photos: From tourists in Sri Lanka to a Cat Extravaganza in London
Sunday's best photos: From Bengal tiger cub in Spain to mourners at funeral in Lebanon
UAE currency: the story behind the money in your pockets
White hydrogen: Naturally occurring hydrogen
Chromite: Hard, metallic mineral containing iron oxide and chromium oxide
Ultramafic rocks: Dark-coloured rocks rich in magnesium or iron with very low silica content
Ophiolite: A section of the earth’s crust, which is oceanic in nature that has since been uplifted and exposed on land
Olivine: A commonly occurring magnesium iron silicate mineral that derives its name for its olive-green yellow-green colour