This is a Gem of a Quiz

Answer: White

The streak test is a method which is used in identifying gemstones. It is best to use a rough piece of gemstone and not a faceted gemstone. A streak plate is a piece of unglazed porcelain. The streak can be obtained by rubbing the mineral across the surface.

Answer: Seven

Mohs' scale of hardness ranges from 1 - 10 and was devised by Friedrich Mohs in 1812. This scale is a relative scale and does not denote the absolute hardness of a mineral. Diamonds are four times harder than corundum but is a 10 compared to corundum's 9. If one mineral scratches the other then it usually is harder, while if they both scratch each other then they are both the same hardness.

Answer: (Mg, Fe2+)2SiO4

Different factors can affect the colour of a gemstone and in some cases the colour comes from the basic chemical composition of the mineral itself. Peridot is classified and an idiochromatic gem and therefore will only be found in shades of green. It is one of the few gemstones found in only one colour.

Answer: Light blue to dark blue, blue green

A member of the beryl family, aquamarine is a transparent to translucent gemstone. It gets its colour from various impurities becoming ingrained during the crystallization process.

Answer: 6 - 6.5

A member of the feldspar group (orthoclase feldspar), moonstone is translucent to opaque and owes its name to the white, almost magical shimmer that resembles moonshine. Moonstone is the birthstone for those born in June.

Answer: Perfect

The most concentrated form of carbon is diamond. Apart from trace impurities such as boron and nitrogen, diamond is composed solely of carbon which is the chemical element that is fundamental to all life. Diamonds are used in jewellery as well as for industrial purposes.

Answer: Amber

Amber is very lightweight and can float in salt water. It is usually warm to the touch and can be scratched easily. Commercial amber, used in jewellery, is most likely reconstituted amber and this makes it harder and less prone to scratches. Amber that is treated in this way does not usually have natural inclusions.

Answer: There is no difference.

Purple is a colour usually associated with royalty and amethyst has been used to adorn rich and powerful monarchs and rulers. Purple amethyst will turn to citrine when heated in a kiln. The largest producer of citrine is Brazil but it can also be found in Argentina, Madagascar, Democratic Republic of Congo, Namibia, Spain and Russia.

Answer: Tourmaline

Tourmaline comes in many colours and two or three colour combinations. These combinations can be seen at different ends of the crystal. Tourmaline sometimes has one colour in the heart of the crystal and another around the outside. A very popular colour combination is pink with a green rind which is called "watermelon tourmaline" (No seeds!)

Answer: Pearl

Oysters of both the freshwater and saltwater environments produce pearls. Within the pearl-sac, specialized epithelial cells secrete nacre which is deposited on the foreign object. Clams and mussels can also produce pearls but the occurrence is much rarer.