Utah Red Horn Coral --

Rockhounding It Today

As far as I can discover, Utah "Rugosa" Red Agate Horn Coral is one of the rarest fossils in the world. It’s not up there with the Burgess Shale pre-Cambrian Fossils. But it’s close.(Read Wonderful Life: The Burgess Shale and the Nature of History by Stephen Jay Gould for that. My wife and I hiked up to the quarry in the Canadian Rockies once.)

This is a review of the Utah Red Horn Coral site from a recent visitor to the dig site, and a link to my original article about when I went red horn coral hunting with my dad and his friends as a teenager.

Since they were around for a very long time, there were lots of opportunities for Rugosa coral to become a fossil and they can be found around the world. (There are other Rugosa coral fossil sites in Utah) but the fossils are usually small, black, and hard to even recognize.)

Rugosa is the name of an extinct order of corals that lived over 400 million years ago. (That is, five times older than the dinosaurs.) for about 250 million years. (That is, at least 800 times longer than humans have existed. See my blog about "Deep Time".)

The only other red-ish agatized Rugosa coral I know of is found in Australia and I was only able find one example on the web.

Other Rugosa coral fossils are mainly calcite, limestone, or something else. There are some in Michigan and more in north Africa. They're gray and indistinct.

When I started sending my dad's rocks to people, I discovered that third-world jewelry factories had simply dumped on the world and destroyed the value of a lot of fossils. I wrote about how and why this happens in the blog, How to Price Rocks.

This seems unlikely to happen to Utah Rugosa Red Horn Coral. My understanding is that the original site has been totally mined out for decades.

My dad helped discover the red horn coral site in the Utah Uinta Mountains. I still have some of the coral that he collected and a piece of native limestone with three perfect large corals embedded in it. I had it listed for sale for a while but I decided to pull it from the listings because I think that the value will just go up and up.

Geologist FINDS RAREST RED HORN CORAL Riley's Canyon RED Horn Coral

This fun video is one in a YouTube channel, Elley Knows Rocks, by someone with actual geological training. At about the 15-minute mark, Elley gives us her theory about why the Riley's Canyon coral are red agate and nothing else is. But the most interesting part for me was to see how hard it is to find any nice-looking Utah red horn coral today. In a day trip, Elley finds half a dozen pieces, but none are like the ones my dad found. I haven't been there in well over fifty years, but I can remember what it was like. She was in the right place, but it has changed a lot.

The biggest change is that my dad and his friends just parked their 4-wheel drive trucks right on the meadow where we found the corals. There was no hiking for us. (The rules must have changed.) As a teenager, I ran behind the truck all the way down the mountain. I couldn't run the first hundred yards today.

But the second biggest change was that I could see that the place has now been worked over thoroughly. The only disturbance in the ground that we could see back then was that the easiest-to-remove pieces of coral-bearing limestone in the ravine had already been dragged up and out. There had been no disturbance in the meadow itself. Now, it's hard to believe that a meadow was ever there.

A second YouTube in Elley's channel is all about how to end-polish a piece of coral and It's a really good starting tutorial. I learned on my dad's home-made lapidary equipment - the hard way at the school of busted knuckles. I recommend Elley's video channel ... it's good stuff. And her trip to Reilly's Canyon is worth watching, especially if you ever plan to go there yourself.

Now ... your reward for reading this is my essay:

The Red Horn Coral Story