Q 01/05

Sapphire is a gem variety of which mineral?

A) Beryl

B) Corundum

C) Quartz

D) Topaz

Answer · why

B) Corundum

Corundum: it is so hard and weather-resistant that its crystals collect in river gravels, where miners sift out many sapphires.

Q 02/05

What score does sapphire earn on the Mohs hardness scale?

A) 7

B) 8

C) 9

D) 10

Answer · why

C) 9

Only diamond and moissanite are harder, which is why sapphire ends up on watch faces and barcode-scanner windows.

Q 03/05

Gem-quality stones of the same mineral as sapphire, but red, are sold under which name?

A) Garnet

B) Ruby

C) Spinel

D) Carnelian

Answer · why

B) Ruby

The red comes from chromium; the two gems are so closely related that some dealers call rubies 'red sapphires'.

Q 04/05

Sapphire is the traditional birthstone for which month?

A) February

B) December

C) November

D) September

Answer · why

D) September

September: its birthstone has excellent toughness and no cleavage, so it holds up well in rings worn every day.

Q 05/05

Sapphires that are any colour other than blue are known in the trade as what?

A) Shadow

B) Fancy

C) Minor

D) Ghost

Answer · why

B) Fancy

They turn up in yellow, orange, green, purple and even colourless, though only the blue ones are what most people picture.