Fossil Preparation
PaleoBond, Air Scribes, Diamond Saws & Rock Splitters

This page describes some common tools & techniques used by paleontologists to repair and trim fossils.  The focus here is on fossil plants because that is my specialty. (See Note 1 below.)  

It is very common to shatter fossils in the field.  When this happens, you need a good rock glue such as PaleoBond.  Also, the rock may not split in a way to completely reveal the fossil.  Air scribes are typically used to remove the excess material covering the fossil.  Finally, you may need to trim unwanted rock surrounding your fossil.  This is easily removed with diamond saws or rock splitters.


This glue is used to repair fossils that were cracked or shattered in the field.  In past years, I used to mark/number the pieces in the field and glue them at home.  But, I found it is much easier to carry a small vial of Paleobond to repair specimens in the field.  This reduces confusion in numbering the pieces and it requires less wrapping.  A word of caution regarding glue accelerators/activators: Use with caution!  They often discolor the rock after 5-10 years in storage!  Just use the plain glue or you may end up with green fossils in your collection!

Paleobond (light 100 formula) used to repair shattered Green River Formation conifer

Pneumatic Air Scribes

Fossils typically require extra work to remove unwanted material to reveal the complete fossil.  This applies to all fossils (plants, insects, vertebrates & invertebrates).  The tool of choice is an air scribe, namely Chicago Pneumatics Air Scribes (model #: CP9361, below: top-left,
for fossil plants and insects). [See Note 2. below, for vertebrates.]  They are basically miniature jack hammers and come equipped with a variety of chisel types.  To power the scribe, an air compressor is required that is compatible with the air pressure specified for the scribe.  The Nikota Twin Tank, 2 HP, 4 Gal w/oil lubrication is a cheap solution and is available in most auto-parts stores.

Chicago Pneumatics Air Scribe; Nikota compressor; before & after images of fossil

There's often excess rock on all sides of the fossil.  This is easily removed with diamond saws or rock splitters.

Diamond Saws

You can spend a lot on a diamond saw!  However, a cheap solution is an inexpensive diamond blade for a hand-held rotary saw.  These can be used as a portable or they can be mounted on a rotary saw table available at most hardware stores.

Diamond Blade on portable saw mounted on table (top); fossil leaf before & after trimming (bottom).

Rock Splitters

Another method for removing excess material is a table-mounted rock splitter (below, left).  However, given the simplicity of these devices, they are often very expensive.  They are cheaper at fossil shows such as the Tucson or Denver shows.  But, two inexpensive alternatives are horse hoof nippers (below, right-top) or tile nippers (below, right-bottom).

Rock Splitter (left); horse hoof nippers & tile nippers (right)

Krylon Acrylic

Using any acrylic sprays on fossils should be avoided.  However, there are cases with highly organic fossil material, such as woods or monocot plants, where these sprays will actually help preserve your fossil.  With some unusual plant fossils, acrylic sprays will help seal the organic material so it doesn't dry out and fall off (see image below and link to further images below).  In these situations, apply the spray immediately after splitting the rock in the field.  I cannot tell you how many times I've unwrapped these woods at home only to find a nearly blank rock!  Again, these fossils are the exception.  You should try to avoid sprays for all of your fossils.  If you use a spray, stick to clear acrylics like Krylon Crystal Clear Acrylic.

Krylon Acrylic used to keep organic material from falling off fossil.

Now you've seen all the tools...

See Images of Fossil Preparation Tools & Techniques


  1. Ve
rtebrate paleontologists generally use a thicker PaleoBond formula as well as a liquid adhesive/glue called Vinac.
  2. For vertebrate fossils, other air scribes are typically used such as the Ingersoll Rand scribe for larger specimens or harder matrix; or the AERO scribe for smaller specimens or softer matrix.  See image at this link.
[Created 07/28/2005]
[Last Updated: 7/31/05]