Q 01/05

Quartz is composed of which compound?

A) Silicon dioxide

B) Calcium carbonate

C) Aluminium oxide

D) Iron sulfide

Answer · why

A) Silicon dioxide

Its atoms form a continuous framework of silicon-oxygen tetrahedra, each oxygen shared between two of them.

Q 02/05

Quartz defines which value on the Mohs scale of hardness?

A) 5

B) 6

C) 7

D) 8

Answer · why

C) 7

Topaz sits at 8 and orthoclase feldspar at 6; the scale was introduced by Friedrich Mohs in 1812.

Q 03/05

By mass, quartz makes up about what share of the Earth's lithosphere?

A) 12%

B) 20%

C) 30%

D) 50%

Answer · why

A) 12%

Only the feldspar group, at 41%, is more abundant; pyroxenes come third at 11%.

Q 04/05

The Ancient Greeks called quartz krystallos, meaning icy cold, because they believed it was what?

A) Supercooled ice

B) Frozen lightning

C) Petrified water

D) Solid moonlight

Answer · why

A) Supercooled ice

Pliny the Elder argued the case by noting it turned up near Alpine glaciers but not in hot countries; the idea lasted into the 17th century.

Q 05/05

The word quartz, via German Quarz, is thought to come from a Polish dialect word meaning what?

A) Clear

B) Cold

C) Shiny

D) Hard

Answer · why

D) Hard

The term kwardy matches the Czech tvrdy; another theory points to a Saxon word for cross-vein ore.