Specimen of the Month: "Sēptārium"

I instantly regretted installing a display during office hours. Thinking my work would be out of everyone's way, I started as the angle of the morning sunlight through our front windows hinted that it was not even 9 a.m. yet. Still, a handful of people already squeezed past my collections cart while I tried to carefully get a specimen under its case and place a display sign before we were to open to the public in an hour. Just like that, a visiting Board member kicked off with the first of many questions we usually have for the Specimen of the Month displays.

The septarian geode I had just placed under an acrylic case wasn't very familiar to me, but to be honest, the Museum has plenty of geological specimens which I could bear to learn more about. So, I didn't have the answer when asked, "Does 'septarian' have something to do with seven--how long it took to form or something?"

Why would I create a display about an object I had no knowledge of? Well, I didn't exactly--this time around I was only setting it up. It was one of the Museum's friendly summer interns, Melissa, who had ventured into the depths of the collection and retrieved this attractive configuration of crystals. It certainly has its physical charm, but there's much more to the septarian geode than that.

The Museum has one septarian geode specimen which has
a quite attractive "front" view. Pieces like this are highly valued worldwide
for their appearance.

Thanks to Melissa's interest in this rock and subsequent research, I too would later learn that geodes like these began as "mud balls" made of clay sediments which had formed around decomposing organisms more than 50 million years ago. The mud balls changed over a long period of time. As they initially dried, they shrank and cracked to leave empty spaces which geologists refer to as "septaria." So, after referring back to the Latin root for this formation's namesake, I found that a septarian geode really just refers to the "enclosure" or inner surface where golden hues of crystals eventually formed. The resulting geode formations are apparently quite prized by many.

Melissa Krizan, Naturalist/Sustainability Intern this summer, chose
a specimen to develop interpretive signage for our Specimen of
the Month display in August.

I suppose my poor timing in setting up the display could be viewed as a chance to unexpectedly learn something new--although I would have quite preferred to be a know-it-all in front of a Board member. More than my poor timing though, Melissa had truly provided me with the learning opportunity. Though we hope that our interns are here to learn from us, it never hurts when the situation is the other way around!