Q 01/05

The sarsens, the huge blocks of which ancient monument, are a rock made almost entirely of quartz?

A) Parthenon

B) Colosseum

C) Stonehenge

D) Great Pyramid

Answer · why

C) Stonehenge

Stonehenge. A core drilled from one sarsen during repairs in 1958 was kept as a souvenir for sixty years; once handed back, it showed grains of quartz...

Q 02/05

Quartz defines 7 on the Mohs scale; which gem mineral defines 8?

A) Topaz

B) Corundum

C) Diamond

D) Talc

Answer · why

A) Topaz

Topaz. Friedrich Mohs picked ten minerals in 1812 so that each one scratches all those below it, so quartz will mark the six softer minerals on his li...

Q 03/05

Milky quartz owes its cloudy white colour to what trapped inside the crystal?

A) Tiny bubbles of fluid

B) Specks of chalk dust

C) Grains of salt

D) Flakes of mica

Answer · why

A) Tiny bubbles of fluid

Tiny bubbles of fluid. Milky quartz is very common, yet the gas and liquid sealed inside it as it grew leave it too cloudy to be wanted as a gemstone.

Q 04/05

The Ancient Greeks called clear quartz krystallos because they believed it was a permanent form of what?

A) Ice

B) Salt

C) Dew

D) Diamond

Answer · why

A) Ice

Ice. They took clear quartz for water frozen so deeply it would never thaw, and the idea is fossilised in our word 'crystal', from krystallos, which m...

Q 05/05

The word quartz is thought to come from an old Slavic word meaning what?

A) Clear

B) Cold

C) Shiny

D) Hard

Answer · why

D) Hard

Hard, as in Czech tvrdý and Polish twardy. That is the favoured theory, though not the only one: a rival account traces the name to an old Saxon word ...