Scanning Electron Microscope SEM - Callixylon

Recently, I found a a very small (7 mm x 3 mm) piece of coalified Callixylon wood from the Upper Devonian Period.  After searching a large pile of New Albany Shale in Clark County Indiana for a while, it was all I discovered.  A little disappointed, I left the site but later studied the specimen with an optical microscope.  To my surprise, it appeared the wood still had its ray lines intact.

After reading a section of Chapter 12 Progymnosperms in the book Paleobotany: The Biology and Evolution of Fossil Plants by Thomas Taylor, Edith Taylor and Michael Krings, I determined Callixylon wood rays are constructed of ray tracheids and ray parenchyma.  In figure 12.16 of the book displays a SEM image of pit membrane of tracheid and I wondered if such detail was still intact on one of these samples?

My microscope became ineffective after 100 times magnification to see something this small. What I needed was a scanning electron microscope (SEM).  Yikes! Those cost a lot of money and I am not a research university or million dollar company.  What to do?

Scanning Electron Microscope SEM

Image compliments of ASPEX Corporation

Fortunately, I remembered my friends at ASPEX Corporation in Pennsylvania who scanned a fossil for me earlier in the year.  They have a great FREE program that lets every day people get items imaged with a scanning electron microscope SEM.  The program is call "Send Us Your Sample".  Just follow these steps:

1) Go to the ASPEX Corporation website and print this form.

2) Fill out the form and mail it along with the sample to be scanned:

ASPEX Corporation
Free Sample Submissions
175 Sheffield Dr.
Delmont, PA 15626

 3) Once ASPEX completes the scan, the images will be posted on their website here.

Note: It should take about 2-6 weeks (depending on work load) for the results to post to the ASPEX website.  Submitters will be notified via e-mail.  Be sure to note on the submission form if you want the sample returned.

While at the ASPEX web site, check out their Name That Sample contest with a chance to win a brand new Netbook. 

SEM of Cornulites

In early March 2010 I sent a number of samples to ASPEX Corporation to be imaged with a Personal Scanning Electron Microscope (PSEM).  It was part of their free scanning promotion talked about in this February 26, 2010 post. One item sent was Cornulites tube from the Ordovician Period.  The fossil was found in the Kope Formation of Carroll County, Kentucky.  Yesterday, I received the results which I now present in this posting.

Binyam of ASPEX Corporation was the analyst and report preparer. He used the PSEM eXplorer (image below) to analyze this fossil (above).  A manual SEM and EDX Analysis was done using Backscatter electron detector (BSED) to collect images under variable pressure conditions (0.15 Torr) and 20 KeV. 

Here is a SEM image with 200 um scale of the area between multiple growth rings.

A even more close up view provided by this image at 100 um scale.  Yikes, I need to clean these fossils better!

Thanks to ASPEX for doing this analysis and imaging!  Visit this weblink for more information about their promotion.

FREE Scanning Electron Microscope Imaging from ASPEX

Yes, you read the title correctly.  ASPEX Corporation of Delmont, Pennsylvania is offering the public the chance to have an item imaged with their Scanning Electron Microscope (SEM).

Image compliments of ASPEX Corporation

According to their literature, an optical microscope achieves a usable image at magnification of 100 times and can go up to 1000 times (20 micrometers).  The ASPEX Personal Scanning Electron Microscope can image an object to 25 nanometers (nm) and has a scanning range of 100 nm to 5 mm.  They go on to stress the resolution is not the only variable to consider when analyzing a specimen.  SEMs provide a more depth-of-field than optical microscopes.

There are a wide range of applications SEMs can be used for and not just in the research laboratory.  ASPEX makes an application for forensics (e.g. like a real world CSI) specifically Gunshot Residue (GSR) analysis.  Other applications that can take advantage of SEM analysis: industrial production quality control, metal quality measurements, aerospace/defense maintenance prediction, and the pharmaceutical production.

All and all this is a great opportunity for amateur paleontologists.  I keep wondering what items would I like to see: foraminifera, scolecodont tooth, ridge in cornulite tube, small fluorite crystals, pyrite crystal, growth lines on modern snail shell, crinoid stem segment or a pore of a bryozoan.  So many possibilities in the microscopic world to explore!

One needs to remember that unlike optical microscopes, SEMs image in grayscale so no color output.

Well, I encourage those interested in exploring this generous offer made by ASPEX Corporation and check out the images already displayed at their website.

How to Participate in the "Send Us Your Sample" Campaign

1. Download and print this form from the ASPEX website.

2. Fill out the form and mail it along with the sample to be scanned:

ASPEX Corporation
Free Sample Submissions
175 Sheffield Dr.
Delmont, PA 15626

3. Once ASPEX has completed the scan, the images and report will be posted on ASPEX's website here.

Note: It should take about 2 weeks [UPDATE: 05/17/2010 I received the results from the fossil of an Ordovician Period worm tube.  See the results at this post.] for the results to post to the ASPEX website, and the submitters will be notified via e-mail. If you want your sample returned, please say so on the submission form.

Remember to follow common sense on sending material to be scanned and also follow all postal regulations for shipping specimens through the mail.

Learn more about ASPEX Corporations Scanning Electron Microscopes by watching this video: