Frequently Asked Questions

What is a Trilobite?

Trilobites, one of the earliest arthropods, first appeared at the beginning of the Cambrian Period, about 521 million years ago, when they dominated the seas. Since trilobites from this era already displayed a high degree of diversity and geographic distribution, it is speculated emergence must have been much earlier. Trilobites, meaning "three-lobed",  went extinct around 240 million years ago.

These hard-shelled prehistoric critters roamed the sea floor and coral reefs in search of food. Because of their great diversity and often perfect preservation in fine-grained rock, they are one of the most popular fossils among collectors.

The common trilobites found in the West Desert of Utah are Elrathia kingii, Asaphiscus wheeleri and Peronopsis instricta. Other more rare trilobites and soft bodied creatures are occasionally found as well.

Elrathia is one of the most abundant trilobites in the world. This trilobite had an astonishing ability to flourish where other ancient animals could not. They patrolled the muddy, deep waters offshore of the ancient continent Laurasia. Elrathia filled the dark benthic zone on the border of very little oxygen and none at all.  

Elrathia kingii and Asaphiscus wheeleri can be found "Complete", whole animal intact with it's free cheeks (two removable pieces on both sides of the center head), or "Near Complete" which is a molt of the trilobite. Trilobites, like other arthropods, had an external skeleton, called an exoskeleton, composed of chitinous material. They shed their exoskeleton just like the common day lobster. For the animal to grow, the exoskeleton had to be shed.  Part of this process included the free cheeks being removed. These exoskeletons are fossils that are found much more often than a complete trilobite. Our estimate is 5 to 6 trilobite molts are found for every 1 complete trilobite found. Sometimes a trilobite can be found with one free check on the side of the top lobe of the trilobite. This type of trilobite was caught in the molting process due to one free cheek being still attached as the molting process includes the free cheeks to detach for the soft bodied animal to work it's way out. 

Where is Septarian Found?

Utah Septarian is a sedimentary rock mined from underground.  These ancient gems are found 20 feet to sometimes 60 feet below the earths surface! They are mined near Orderville, Utah. 

Septarian is commonly seen in Madagascar, Morroco, New Zealand, the UK and Utah. Particularly, the Utah Septarian is very decorative, compared to other Septarian, with it's beautiful and bright varied calcite (Calcium Carbonate) interiors.

If a Septarian product has a crack, is this cause for alarm?

No. The Nature of Septarian and how it is found 20 to sometimes 60 feet under tons of earth means that Septarian products can occassionally have a hairline crack.  This is indeed the nature of the rock, and it is much more unlikely for a product not to have any cracks.

What Minerals can be found in a Septarian?

The dominant minerals found inside Utah Septarian are Calcite, Aragonite (or Siderite) and Limestone. The Calcite found is very unique from geode to geode. It varies greatly in color...from a smoky dark to a honey yellow and an orangish and/or white hue. Not only does the color or the Calcite differ vastly in it's brightness, hue, and tone; the Calcite crystal interiors vary tremendously as well in the shape, size and shine of the crystals. Aragonite is the beautiful shades of brown seen outlining the Calcite and making up the crack formations. Grey Limestone makes up the exterior. Other less common minerals found inside Septarian are Pyrite and Marcasite. 

Another mineral that is occasionally found inside a Septarian interior is Barite that is seen in the form of a crystal. Barite crystal is very distinguishable from the calcite crystals appearing opaque or translucent in color with a long crystal formation. The size of the Barite crystals that are found vary. Sometimes the crystal is very large inside the interior cavity; other times, on more rare occasions, the crystal will be attached on one side of the hollow cavity and extend to the other side, where it's also attached; and occasionally we find a small cluster or single barite crystal nestled inside among the smaller calcite crystals.

Quite often, due to the Septarians formation, the remains of marine fossils can be seen....Sometimes these fossils are quite distinguishable, and sometimes you only see a small remnant. Most commonly a cross section view of the fossil is revealed after the Septarian is cut or sliced open; however, we have some collection pieces where the Septarian geode has been broken open (instead of cut) to see an ammonite sticking out from the interior or a crab nestled inside!

Each Septarian is truly unique!

What is a Septarian and how did it Form?

Septarian is a sedimentary rock that formed in the Age of the Dinosaur....the Cretaceous period, approximately 66 to 145 million years ago. Septarian started out as a concretion (mud ball). A concretion is a hard, compact mass of rock that often forms around decaying organic matter. In the case of Septarian nodules, the concretions formed around decaying sea-life in a marine environment. The formation of these mud balls came from having just the right environment present....water, calcium rich organic matter (shells from dead marine creatures), and bentonite clay.

Exactly how the radial patterns form in a Septarian nodule concretion is still a mystery. One possible way, the way which is most popular and the explanation we use, is the dehydration of the clay-rich core of a concretion, when the water receded, causing it to shrink and crack. Another speculation is the cracks forming due to the expansion of gases produced by the decay of organic matter within a concretion. Earthquakes have also been suggested as another mechanism. Whichever process it is, we know that the common shapes seen radiating from the center of a Septarian were once cracks that were formed from one or several of these processes. 

Millions of years ago, during the Cretaceous period, the Gulf of Mexico (Western Interior Seaway, or Cretaceous Seaway) extended into what is now Southern Utah. The decomposing Calcium rich seashells, from possible volcanic activity, had molecular attraction to the sediment surrounding them (betonite clay), forming mud balls as they were slowly rocked back and forth in the shallow waters. Some mud balls were very large, much bigger than a basketball, and others stayed small, similar to a softball.  As the water receded, the balls dried and cracked. When the water returned, deposits of calcium rich sediments covered the mud balls with the minerals seeping into these cracks. Due to their bentonite content, the mud balls eventually shrunk trapping the minerals inside.

Limestone, Aragonite and Calcite are all formed when Calcium Carbonate (from the sea shells) is present. So we know that there was an abundance of Calcium Carbonate for these minerals to form.  Inside the mud balls the mineral Aragonite formed and became the brown edge outlining the formed Calcite interior.

Approximately 75 to 80% of Septarians are Nodules which have a solid interior filled with Aragonite and Calcite minerals. While approximately 20 to 25% of Septarian mined have a hollow calcite crystal center which is believed to have formed from the gasses given off from the decaying sea life trapped inside, creating a void for the crystal formation. 

Septarian name comes from the Latin word septum meaning a dividing partition between two tissues or cavities.