The idea for this mosaic started when I found a couple trilobite fossils at Paxton Gate, a rock and curio shop in Portland, Oregon. At ZRS Fossil in Minneapolis (Uptown) I found some more. At a rock show up near the Twin Cities I found some jasper slabs. Later I found some other slabs at a rock shop up along the north shore of Lake Superior. Eme and Neil had gathered a bunch of metal from along the railroad tracks in Winona.
All these were tossed in a tray in the studio for several months. The studio was a disaster at the time. I wasn’t doing any mosaic or sculpture work at the time, the mess was too crazy bad. Last month I cleaned the studio. Finding the tray with the materials on one of the shelves, I decided it was time to start the mosaic.
Jasper is from the chalcedony/quartz group. It is an opaque microcrystalline variety of quartz that contains up to 20% foreign material. These materials are what determine the color and appearance of the stone. Because of these foreign materials, jasper is rarely uniform in color, it is usually multicolored, striped, mottled and/or spotted.
I believe that the three yellowish stone slabs in this mosaic are either Marsten Ranch Jasper (most likely) or Stone Canyon Jasper. The single slab of dark brown jasper is most likely be Burnt Ranch Jasper, but that’s based on a single photo example on the web, so I may be wrong about it.
Marsten Ranch Jasper probably has its origin as petrified wood. The wood structure has been lost, so it would be more properly referred to as a limb cast. This jasper has bright contrasting red, yellow and green colors that create great slabs.
Stone Canyon Jasper originates in the California central coastal region in an area half way between Los Angeles and San Francisco.
The fossils are Diacalymene trilobite fossils from the Anti-Atlas Region of Morocco, from the Ordovician period (the second period of the Paleozoic Era, which began 485.4 million years ago, following the Cambrian Period, and ended 443.8 million years ago, when the Silurian Period began).
Trilobites were a very diverse group of extinct marine arthropods. They first appeared in the fossil record in the Early Cambrian (521 million years ago) and went extinct during the Permian mass extinction (250 million years ago). They were one of the most successful of the early animals on our planet with over 25 thousand described species, filling nearly every evolutionary niche. Due in large part to a hard exoskeleton (shell), they left a excellent fossil record.
Every now and then, Eme and Neil go hunting for metal pieces for me. They roam around the back alleys and railroad tracks looking for interesting scraps of metal. I have several bins of metal they’ve rounded up. One of the pieces I’m planning on using in this mosaic is a strip from a shipping container seal. It has numbers embossed into it. I’m also planning to use several strips of varying lengths and thicknesses, and a couple flat pieces.
Adding Sculptural Effects
The trilobites are thick enough to add a sculptural effect, as is most of the metal. I didn’t want the slabs and the larger pieces of metal to be flat elements, so I built up the surface below where they will be using foam, mesh drywall tape and mortar to add height to the work.
Burnt Ranch Jasper
Diacalymene Trilobite Fossils