About Rocks and Fossils

Fossils
Fossils are the most useful guide to understanding the history and development of life on earth, they are a source of much wonder. Inevitably some species may be forever lost, as prevailing conditions would have prevented fossilisation. Geologists have used fossils to date rock strata by the type of fossils embedded providing a valuable gauge for finding mineral deposits and drilling for oil.

For starting a collection some of the small inexpensive Madagascar Ammonites Perisphinctus or Clioniceras make an excellent beginning. Whether starting or adding to an existing collection each one of us may be drawn to a different time period or type of fossil, be it Cambrian trilobites, Devonian shells and corals, Jurassic dinosaurs, Ordovian, Silurian, or Cretaceous periods, we find insight into prehistoric times on earth through studying fish, animal, plant, insect, bone and teeth fossils. Just think about the wonderful pictures of insects and plant life "frozen" in time and captured in amber.

Rocks
Rocks are the material from which the earth and indeed the moon and planets are made.

They are usually grouped into three general types:

• Igneous rock; Formed by solidification of molten rock such as granite, mica, basalt etc., all varying in colours and chemical composition.
• Metamorphic Rock; Formed through the altering of igneous and sedimentary rocks by heat and pressure such as marble and quartzite.
• Sedimentary Rock; Formed by accumulation of rock waste at the earth's surface such as sandstone, limestone, shale, chalk and ironstone.

Whilst many rocks are millions of years old, the fascinating thing is, that as the earth's crust moves and changes new forms of rocks emerge. Thus the discovery of new rock types is an ongoing joy. An example of this is the Orbicular or Ocean Jasper recently discovered off the coast of Madagascar, it can only be seen at low tide and only collected by boat. It is a fascinating form of Jasper still being studied. The beautiful Labradorite, no longer found in Nova Scotia where it was mined in the 19th Century, has now, been re-discovered again in Madagascar. It has the most wonderful luminescence and is sometimes known as Spectrolite.

Minerals
Minerals are some of the most remarkable and beautiful naturally occurring materials. Quite apart from their many useful properties in industry, the colours and crystalline structures make suitable specimens some of the most desirable decorative and display pieces and ornaments. Many such as gold, copper, nickel, cadmium, potassium, phosphorous, lead and silicon to name a few have been of immense industrial importance.

The Quartz groups offering a true A-Z of fabulous crystals from amethyst to zeolites. Natural iron pyrite with its incredible cuboid growth pattern, Lapis lazuli once ground down to provide the wonderful blue pigment that artists used in ancient religious paintings before the advent of oil based paint, and of course the many cut and polished minerals made over centuries into wonderful mineral ornaments and vessels, malachite, agates, chalcedony, opal and jade. All prized for their beauty for centuries as precious objects. In their natural state they represent some of the most beautiful works of art.