Trilobite Mosaic -- Stone & Metal Mosaic

Work in Progress

January 9, 2017

Beginning the Work

Whereupon I Have An Idea

Since my last post (before heading out for a three-week vacation) I’ve been pondering what I really want to do with this  mosaic. It’s a big deal to deconstruct a mosaic that isn’t turning out like you want. It’s also a bit deal to spend the time i t takes to make a mosaic and end up with something that isn’t as good as it could be. I’m always concerned at this point in a work, that what I “see” in my head won’t make it out into the world. Sometimes when that happens the result is just fine, or even better than what I planned. Other times, well, I end up with something that isn’t quite what I wanted it to be and that is discouraging.

This morning when I woke up I knew what I wanted to call the mosaic and what I wanted to do with it. The name — at least at this point — will be Travail/Travel. I have the description/message for the piece almost written, but I’m not sharing it until the work is done.

Adding More Sculptural Effects

Tonight I did more work on building up the base for the mosaic. In the images you can see where I’ve built up the area around the trilobites to suggest the path they are taking, have taken with higher areas in front and to the side of the trilobites, and lower areas behind them. I want to suggest movement. I want it to look like they are… not struggling, but that they are having to work hard to make their progress across the land.

I have no idea what  conditions trilobites encountered in their lives, but in my head they leave tracks in the sand that are smoothed out pathways.

Stone Preparation — Hammer & Hardie Work

When I do a stone mosaic I generally use a mixture of cut and uncut stone along with the occasional stone slab. The uncut stone is stone that I’m using just as I found it in the river, along the lake shore, on the hillside, or on the paths or trails. I might slice with the lapidary saw it to make the depth/height of the stone appropriate for the particular mosaic, but I don’t change the general size or shape of the stone.

The cut stone can start out as a found rock, purchased slab (or one I’ve sawed from a larger rock), or a stone tile from the discount flooring store in Chicago. I use the hammer and hardie to cut the stone into smaller and smaller pieces — tesserae — until I get the size I want. If the tesserae have manufactured/sawed edges I make a final cut with the hammer and hardie to split it half. This allows me to turn the manufactured/sawed sides down so that no perfectly straight edges show.

I’ve been cutting and testing several types of stone for the background of the mosaic. I don’t really have stone that is the exact color I want — an issue for mosaic artists since we cannot simply blend new colors. I first cut up a dark orange/rust-colored travertine limestone which didn’t look right when I did the test for it. I also cut up some reddish-brown marble. It might work color-wise, but it’s a total disaster  to cut… very irregular due to the veins and inclusions. I decided that it would be way to frustrating to try to cut up enough tessarae for the mosaic using this stone.

So, after a lot of thinking, and a lot of digging though my inventory of cut up stone, I’m returning to an earlier choice for the background stone — a deep yellow travertine limestone. Some of the trilobites have curious yellowish highlights which I think will look good with the stone.

While I was going through my inventory I found a largish rock that I picked up somewhere — no clue where though. It’s a variegated sandstone with some really interesting sedimentary banding. Since it’s a super soft sandstone I was able cut it into chunks using the hammer and hardie. I swapped it out for the dark brown jasper(the Burnt Ranch Jasper) and I think it works better.

Next Steps

I don’t think I’ll have time for working on the mosaic tomorrow, but if I do I will be cutting more limestone tesserae in preparation for beginning the construction.

December 31, 2016

Planning Stage

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.

Found Metal

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.


24″w X 15″h

Trilobite fossils, found metal, travertine limestone, jasper.

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