What is it?
Desert roses are petal-like crystals of gypsum.

Where does it come from?
The Sahara Desert in North Africa.

How is it formed?
A desert rose grows in the desert as sea water evaporates under the hot sun.
They are found in regions where oceans are drying up (closing).

There was once a great ocean called the Tethys Ocean that separated the continents of Africa and Europe.
The Mediterranean Ocean is all that remains today.
As the continental plates of Africa and Europe continue to collide the Mediterranean becomes a little smaller and Africa gets a little closer to Europe every year!

Did you Know?
Desert rose crystals are brown because they contain desert sand.
The Sahara Desert in North Africa is 9 million square kilometres – that’s as big as the USA!

If you break a leg or arm your doctor might make a cast out of powdered gypsum called Plaster of Paris.

Gypsum is used to make plaster of Paris

What is it?
Quartz is a naturally occurring mineral that forms in hexagonal shaped crystals.

Where does it come from?
Quartz is a very common mineral that can be found in rocks from all over the world.

Did you Know?
The Ancient Greeks called quartz krystallos or “ice”. This is the origin of our word for “crystal”.

Quartz is the second most common mineral in the Earth’s crust.
In case you were wondering, Feldspar is the most common mineral.

Quartz feels cold to the touch because it is a good conductor of heat.

The Romans used large quartz spheres to cool themselves on really hot days.

The Romans used quartz spheres to cool themselves on hot days

They also used crystals of quartz to sterilize battle wounds.

They focussed the sun's rays through a quartz crystal.
The burning of the wound actually sterilized it. Ouch!

You can also do the same thing by using a magnifying glass.

Myths and Legends
People used to believe that quartz crystals were fragments of fallen stars.

About 470 years ago during the renaissance period, people believed that quartz was compacted ice that could no longer melt.
Fortune tellers traditionally use a crystal ball made of quartz.

Where can you see Quartz?

Beaches: are usually composed pebbles and sand that are made of quartz

Deserts: Sand dunes and deserts are made of fine grains of sand that are blown by the wind.

Lenses: Glass is composed of 70% quartz. Glass is used to make lenses to help us see.

Windows: Glass windows let light in but prevent heat getting out.

Glasses: For thousands of years we have used glass to make wine glasses and other containers for liquids.

Clocks: Quartz is used in clocks and watches because it vibrates at exactly 60 times a second if you pass electricity through it.

What is it?
Amethyst is a purple coloured variety of crystal quartz.

Where does it come from?
Brazil and Uruguay in South America. It can be found in many other places too.

How is it formed?
Amethyst crystals grow in cavities and holes left behind when lava bubbles and cavities in basalt lava are preserved.

Nodules of amethyst can be several metres in diameter. These are often called "caves".

Myths and Legends
Throughout history amethyst jewellery was favoured by the rich and powerful.

Amethyst is traditionally worn by bishops to signify religious devotion.

In Ancient Greece people used to believe that you would not become drunk if you drank from an amethyst goblet.

Amethyst was once thought to prevent drunkenness

What is it?
The mineral called Labradorite is a variety of plagioclase feldspar.

Where does it come from?
Labradorite was first discovered on the Island of St. Paul on the Labrador coast in Canada. It can also be found in Madagascar, Russia and Finland.
Much of the Labradorite today comes from Madagascar.

Key Facts Labradorite is often used as a semi precious stone in jewellery making because it reacts in an interesting way with light.
The fledspar crystals are arranged in layers that produce bright flashes of blue, greens and gold when viewed at different angles in the light.

This is called the Schilleren effect after an Austrian Mineralogist.

What are they?
Agate is a variety of quartz made up of tiny crystals called cryptocrystalline quartz.

Where do they come from?
Brazil in South America. They can also be found in many other places.

Geodes grow in bubbles of lava.

How do they form?
When a volcano erupts, hot liquid rock called magma is forced up by pressure onto the Earth’s surface.

With the release of pressure gas bubbles appear in the lava as it flows out.

The same thing happens if you shake
a bottle of fizzy drink before opening it.

As the lava cools and hardens after an eruption gas bubbles can become preserved.

Over thousands of years, warm mineral-rich water flowing through the rock enable quartz crystals to grow inwards from the outside.

If the crystals are very small they are called agate.

They fill the bubble or cavity to create a nodule called a geode.

Create your own mini eruption.
Shake a bottle of fizzy drink and open the lid quickly.

What is it?
Pyrite is a brassy looking minerals that is described as having a metallic lustre.

In the past, pyrite was often called "fools' gold" because of it is shiny, yellow and heavy. At first glance it looks like real gold.

Key Facts
Ammonite fossils are sometimes made of pyrite nodules.
Pyrite fossils tell us a lot about conditions on the seabed at the time when the creature were alive.

Pyrite fossils indicate that there was not much oxygen around but plenty of organic carbon perhaps from peat or coal.

If you are lucky enough to find some gold, here are a few tips to help you tell if it is gold or fools gold.

  Density

Strange but True:
A new species of snail has recently been discovered living deep at the bottom of the Indian Ocean.

It lives close to the hydrothermal vents of black-smokers.   It has developed interlocking scales made of pyrite. These are thought to be for protection from predators. This snail has not yet been given a name. What name would you give it?
	Photo: Stefan Bengtson - Swedish Museum of Natural History

In 1576 Martin Frobisher was commissioned by Queen Elizabeth 1 and set out on three voyages in an attempt to find a route to China via Canada by the fabled North West Passage.  But more importantly he hoped to find riches.  He did not discover a North West Passage but found large deposit of what he beleived to be gold. He returned home with some 1000 tons of it which was duly locked up in The Tower of London for safe keeping by the Queen's command. Unfortunately the hoad was soon discovered to be nothing but Fools' Gold.

What is it?
Aragonite and calcite both have the same chemical make up - calcium carbonate. They have different structures.
When a mineral can have two different structures it is said to be polymorphic.

Where does it come from?

Aragonite grows in many places. The first specimens to be described came from the region in Spain called Aragon. This is why it is called aragonite. Aragonite can also be found in Morocco, Mexico, France plus many other places.

How does it form?
Aragonite often forms in ball-like clusters of crystals through a process called crystal twinning. Each crystal has a hexagonal cross-section.

This type of aragonite formation has been given the nick-name "aragonite sputnik" because of it similarity to the Russian space satallite from the 1950s.

Pearls are made from aragonite.
Most shellfish such as oysters, mussels and nautilus use aragonite to build their shells.
Over millions of years, aragonite will convert back into calcite. For this reason we do not find fossils made of aragonite, only calcite.