Types of rock

Some minerals are very rare and pretty — we call these gemstones and they are used to make jewellery. Can you name any gemstones?

What is the most  famous gemstone? Is it a Crystall or a diamond? The answer does  not only  look beautiful in jewellery but they are also used in drills and saws for cutting.There are three main groups of rocks — these are sedimentary, igneous and metamorphic.

Trilobites!

Trilobites are one of the oldest animals that first lived on the Earth. They lived in the Cambrian Period and early Ordovician seas. A prolonged decline then set in before they finally became extinct in the Permian Period, about 250 million years ago.

Trilobites were arthropods—like crustaceans, spiders and insects. They are divided into three parts from head to tail (head, thorax and tail) and from side-to-side (the central axis and two lateral lobes). Hence their name 'trilobite'.

Ammonite cycle

An Ammonite bobs
around happily around the sea...  

But then dies 

and falls to

 the sea floor...

                                                             

The soft parts decay

 leaving the shell to be buried in sediment...

Then is changed by heated

 water and pressure over millions of years...

Into the fossil you find in the beach!

400 × 300 - allposters.co.uk

This is nautilus.
It is the ansester of a ammonite.
they are found today and are ofen in this colour.

   Trilobites are fossils like Amonites.

They are like bugs but much older.They are found in the jurassic period alive. This was millions of years ago so we would never find them living today.Desserts-like places are good areas to look for them because they used to live in sand.

This is a diamond.
They are one of the rarest gems in the world.
they can be pink,red,yellow,blue and white.
Lots of people put them in jewlerey such as
necklaces.

This is calsite.
                                              they can come in  lots of different colours such as blue,red and white.
                                               they are quite common and easy to find. It is very swirly when you polish it.

       This is an amethyst.
                                            They are purple, pink and lots of other colours.
                                            They are differcult to tell from other stones such
                                            as Blue John.

This is amber.
incects and seeds get traped in sap ( thats stuff thats in a tree.)
and the sap turns hard over millions of years which makes amber.
This leaves an orange/yellow/green stone.