How to Prepare Limestone Fossils

Remove any sand, silt or other loose material around the limestone fossil with a soft brush and a hobby knife.

Use a power grinding tool, such as a Dremel tool, to remove large amounts of matrix rock from around the fossil to make the specimen easier to handle and work with. Use a sharp carbide bit to avoid removing large chunks of rock and damaging the fossil.

Remove the matrix rock closer to the fossil with a fine hand chisel and mallet. Work up to the rock within a few millimeters of the fossil.

Use a pointed tool, such as a large sewing needle in a pin vice or a dental pick, to work at the last bits of matrix left on the fossil. Be careful not to damage the fossil by exerting too much pressure. Use a microscope at 5 to 10 power to do extra fine work, if necessary.

If desired, apply a consolidant to protect the limestone fossil once it is free from the matrix. While it is usually not necessary, using a consolidant, a type of hardener that penetrates the rock, can help to preserve the fossil. Allow the fossil to dry completely before proceeding.

In the glass jar, dissolve a resin such as Vinac B-15 or Butvar B-76 in acetone at 1 part resin to 32 parts acetone.

Brush the mixture onto the fossil, allowing it to penetrate the rock. Allow the resin to dry thoroughly.