Category Archives: Rock/fossil of the month
March – Ironstone
Iron makes up a full 35% of the whole Earth, though most is sequestered within the metallic core, with the crust containing around 6%. It is an important rock commercially, being smelted to make iron and steel. High grade deposits, often comprising more than 70% iron, were laid down in the Precambrian, around 2 billion [...]
on March 8, 2009 Leave a comment
February – Woolly Mammoth Tooth.
Mammoth lived on most of the continents in the Northern Hemisphere during the last big ice age 70-10,000 years ago. Woolly Mammoths were about the same size as Indian elephants are today and covered in a layer of coarse hair. They are a good indicator of a cold climate and tundra or Steppe [...]
on February 3, 2009 Leave a comment
January – Flint
Flint is the dark grey to black nodular material commonly found in chalk. It is Cretaceous in age (146-65 million years old). Flint breaks with a pronounced conchoidal (curved) fracture creating sharp edges. This feature was exploited by early man to create edged tools.
It is made up of a mineral called Chalcedony, [...]
on January 7, 2009 2 Comments
December – Diamond
The name Diamond comes from the Greek word Adamas meaning indestructible. Diamonds are the hardest rock on Earth.
Diamonds form between 120 – 200km below the surface, in the Earth’s mantle, in patches amongst mantle rocks called peridotites and eclogites. Study of these rocks tell us that the material from which diamonds form is sea [...]
on December 1, 2008 Leave a comment
November – Ammonite
Ammonites are coiled relatives of the octopus (Cephalopods) and became extinct at the end of the Cretaceous Period around 65 million years ago.
Below is an image of a Harpoceras, which lived during the Jurassic Period. These fossils can be found in the Upper Liassic shale (Whitby Mudstone Formation) which crops-out widely across Cleveland and the [...]
on November 1, 2008 Leave a comment
October – Gryphaea
This fossil is easy to find on the beach anywhere between Redcar and Saltburn. Often known as a Devil’s Toenail.
It is a relative of they oyster and lived on the seabed in large numbers. This shell had two parts, one much larger than the other. Sometimes you find them still joined [...]
on October 8, 2008 Leave a comment
April – Bulschite