What is a Fossil? A fossil is an organism, creature, plant or burrow that lived millions of years ago. Fossils have the same density as rocks and weigh roughly the same. Fossils are preserved in rock or clay. The first form of life evolved 4 billion years ago, but the first visible life was 2 billion years ago. Life on land first appeared 380 million years ago. Igneous is a name for volcanic rocks, you will not find Fossils in these rocks.
How Fossils are formed? 1. The creature dies and sinks into the sediments (sand or silt). 2. Layers of sediment build up on top, causing a massive weight, the lower sediments become rock, under pressure, the fossil becomes mineralised (replaced by minerals) often Calcite. 3. Various factors, brings the layers lower (often: Plate movement/tectonic movement, Water erosion). 4. Quarries are built and fossils are found; alternatively they get eroded by the forces of nature.
What do fossils look like? There are many types of fossils, each one is unique. You can recognize a fossil from it's texture and color. Fossils have different texture, from plain rock. Fossils often have a different color from the natural rock.