What Is a Fossil? A Beginner’s Guide to Fossils and How They Form

Have you ever wondered what a fossil is or how fossils are made? In this guide, we’ll explain the basics of fossil formation, why fossils are important, and how you can start your own fossil collection!

A fossil is the preserved remains, impression, or trace of an ancient organism. Fossils are typically millions of years old and include things like bones, shells, leaves, teeth, and even footprints.

Fossils can give scientists and collectors a glimpse into Earth’s distant past. From ammonites to dinosaur teeth, each fossil tells a story of life long before humans existed.

Understanding how fossils form helps you appreciate just how special they are. Most fossils are formed through a process called permineralisation, where the original material is slowly replaced by minerals over time. Here’s how it works:

1. The organism dies – For example, a sea creature like an ammonite sinks to the seabed.

2. Burial in sediment – It gets buried by layers of mud, sand, or silt.

3. Mineralisation – Over thousands or millions of years, minerals seep into the remains. At this stage the sediment starts to become rock, preserving the shape of the organism.

5. Fossil discovery – Erosion or excavation brings the fossil to light again.

Fossils are crucial for understanding the history of life on Earth. Scientists (paleontologists) study fossils to:

• Learn about extinct species

• Understand past climates and ecosystems

• Track the evolution of modern animals and plants

For collectors and fossil lovers, they also offer a fascinating connection to natural history's as well as making stunning display pieces.

Looking to buy real fossils online? At The Fossil Shop, we offer genuine, affordable fossils perfect for beginners and seasoned collectors alike. 

Here are some popular options:

• Buy Amber with Insect Inclusions – Real amber containing ancient insects—nature’s own time capsule.

• Ammonite Fossils from the UK and around the world  – Including beautiful cut and polished ammonites showing intricate inner chambers.

• Spinosaurus Tooth Fossil – A boxed dinosaur tooth from one of the largest carnivorous dinosaurs.

• Fossil Fish from the Eocene – Exceptionally well-preserved fossil fish, ideal for education or display.

Explore more in our full fossil collection! 

Whether you’re drawn to fossils for display or simply want to learn more about Earth’s history, they offer a unique blend of science, beauty, and discovery. With genuine fossils available from as little as £15, it’s easy to start your own collection.

Discover your next fossil today at The Fossil Shop — where history comes to life.