Fossilized Oceans: Beautiful Agatized Coral Reefs

With this post, CoralEverAfter expands from just coral conservation of present-day corals to appreciation of their fossil history – and maybe a glimpse into the future. I’m a nerd, through and through, right down to the rock collection I’ve had since I was a kid.  However, last year, everything changed.  My husband went to Australia and brought me back some opals – in the rough.  He knew I had my Gryphon band saw for cutting live corals, so he thought the hard part was over (this reminds me of when I found that *free* fish tank at a yard sale that started my reefkeeping obsession).  Well, I ended up with a slab saw (to cut the rough into something more workable), and then I ended up with a cabbing machine.  And, of course, I couldn’t start with the opals; I had to practice!  So I started buying rocks…and got addicted.  But then, I found fossilized oceans.  More specifically, agatized corals that were once part of an ancient reef. 

So now, not only am I interested in reefkeeping and scuba diving, I’m also into coral lapidary arts.  But, it doesn’t stop there.  Ooooh no… Because what’s the point of having all these pretty rocks just stored up??  So, I started metalsmithing copper and silver.  I already bead, so now I have pretty much the whole lifecycle of jewelry. I hope you enjoy the amazing variety of coral polyp structures, mineral colors, cyanobacteria structures, preserved deathbeds of clams, and other finds on these ancient coral reefs from fossilized oceans.

Indonesia Agatized Coral and Marine Life

The variety of patterns and colors in Indonesian agatized coral and other marine life is truly stunning. Some are nearly entirely agatized, leaving little traces of the original flower-patterned mineralization. Others, leave just the polyp structure, resulting in an incredible field-of-flowers pattern. But, one of my absolute favorites isn’t even a fossilized coral; it’s “Script Jasper,” which is a mortality plate of clams made of vibrant oranges, puce, and small crystal patches.

United States Agatized Coral and Marine Life

Southwest United States:

While most Utah agatized coral comes in varying shades of browns, grays, and yellows, the Red Horn Coral (Lophophyllidium sp.) stands out, not only amongst Utah corals, but is probably at the top worldwide for its coloration, patterns, and specimen quality. Another red fossilized coral is found in Arizona. Arizona fossilized coral is a unique combination of red jasper with a soft yellowish calcite center and bits of sparkly crystal druzy. While they may not make the highest quality cabochons for jewelry, they are certainly interesting in structure and coloration. But then, there are the Michigan corals. They deserve their own paragraph.

Midwestern United States:

Probably the most infamous fossilized coral is the Michigan Petosky Stone, known for its gray body and darker gray eyes. But, there are so many more corals overshadowed by the Petosky. Take, for instance, the lowly chain coral (Halycites sp.). What a fascinating coral structure that looks like a chain necklace! Then, there are Charlevoix stones, Cladopora, and so many more! Although I don’t have examples here, other parts of the Midwest are home to lovely fossil corals.

Southern United States:

While the Petosky stone probably holds the most popular title, Florida’s Tampa Bay agatized corals are downright breathtaking. However, if you’re a coral purist, you may find yourself saddened that very few of the specimens display any remnants of the coral polyps. These agatized corals are so fully agatized that very few traces of the original structure remain. In the slideshow below, the orange piece shows miniscule traces of the original polyps along the white outer edge.

Northwestern United States

If all the fossilized corals in the United States weren’t enough, there’s other fossilized sea life, particularly Stromatolites and Oncolites, which are various microbial remnants, primarily mats and orbs of cyanobacteria. And… let’s not forget the famous Turritella agate (although it’s a freshwater snail species).

Morocco Agatized Coral and Marine Life

It’s incredible to me that one of the most dazzlingly yellow pieces here is stromatolite (microbial mat, primarily cyanobacteria). The ketchup-and-mustard combination, swirled together amidst crystallized valleys, creates a stunning piece. In contrast, while the Actinocyanthus coral cabochon may not boast spectacular coloration, it compensates with exquisite detail in the polyp structure. Some specimens simply look like modern specimens filled with resin; they’re incredible.

Mexico Agatized/Crystallized Coral

I rarely find agatized coral from Mexico (in fact, I only have two slabs), but both are extraordinary. They feature botryoidal formations (bubbly-round structures), crystals, and agate mixed amongst the jasper in varying shades of pinks, grays, and browns.

United Kingdom Agatized Coral

My only specimen from the United Kingdom is what I believe is this Lithostrotion coral. It features crystalline tubes surrounded by a dark jasper. No polyp structures are evident.

Unidentified Locale Agatized Coral and Marine Life

These are all unique pieces obtained from various sources, but they also came without any origin information. If you have any insights to these pieces, please let me know!

Conclusion:

Agatized corals are a great way to learn about ancient fossilized oceans and the predecessors to our current coral reefs. By studying the past, embracing the present, and planning for the future, maybe we can continue the fairytale of CoralEverAfter with a happy ending.

To Learn More:

If you would like to learn more about fossilized corals, their identification, and their structures, this website *rocks*!