Caverns are known for housing many beautiful formations. One, perhaps lesser-known occurrence, is a phenomenon called anthodites. Described as a rare type of formation, they are truly exquisite and a fine example of the Earth's unique treasures. It is said there are only a few places in the world where these jewels of nature are opened to the public to see.

Credit: Leigh Goessl/All rights reserved

This cluster of anthodites gives a "spiky" appearance. A nice example of a "cave flower" on display at Skyline Caverns, located in Front Royal, Virginia.

What Do Anthodites Look Like?

Anthodites are often referred to as the “Orchids of the Mineral Kingdom” or “cave flowers” - and they really are extraordinary formations. Almost pure white in color, anthodites become “spiky-looking’ in nature as they grow, giving its flowering appearance. However, in the earlier stages they have more of a powdery and/or sugary look.  While some scientific information has been documented about them, for the most part, experts are mystified as to how anthodites form.

Anthodites at Skyline Caverns
Credit: Leigh Goessl/All rights reserved

A photo of anthodites I took in 2012 which shows the various growth stages. Some appeared to have been in the very early stages before growth was interrupted.

What is Known About Anthodites?

On one of the tours I took at Skyline Caverns, one of the handful of places in the world these formations are on public display, the guide said that many scientists have come to Skyline to examine the anthodites, however, much is still unknown. It is not entirely understood how anthodites grow and what environmental conditions occur to encourage their growth. While there is a lot to still be discovered about anthodites, one thing that is known for certain is that breaking the vacuum seal causes anthodites to stop growing (more on this in the next section below).

Anthodites are white in color and are typically made up of calcite or aragonite or have a combination of the two. They are both forms of calcium carbonate, but become crytallized differently. 2

James Van Gundy, in an article published on the Universities Space Research Association (USRA) website, explains more about how anthodites form. 3

"Their mode of formation is not well understood, but they presumably form in air-filled chambers by the slow precipitation of calcium carbonate from thin films of water that are held to their surface by capillary attraction.”

Van Gundy further elaborates that anthodites rarely have other minerals than the calcite or aragonite.

Some say the mystery surrounding anthodites adds to their beauty. One thing is for sure, nature guards this secret well.

Anthodite stages of growth
Credit: Leigh Goessl/All rights reserved

In this image, several stages of anthodite growth can also be seen. On a tour I went on many years ago at Skyline, a guide  referred to the first three stages as "sugar", "flour" and "icing" before reaching fully grown anthodites (fourth stage). In recent tours I have been on, I have not heard anthodites described this way, but I tend to agree with those descriptions. What do you think?

Anthodites at Skyline Caverns

There is a wonderful collection of anthodites found at Skyline Caverns, which is in Front Royal, Virginia, located at the northern end of the beautiful Shenandoah Valley. I’ve taken this tour numerous times and never cease to be amazed at viewing Mother Nature’s amazing handiwork. The detail of these formations is amazing and seeing them is a very memorable experience.

In 1937, a man named Dr. Walter S. Amos had discovered a sinkhole in Front Royal. He suspected there was a cavern beneath and after further examination it turns out he was right. Upon digging, he discovered an astonishing network of connected cavern rooms, most of which were not obstructed once getting into the first room. In all, after discovering the underground network of rooms, only 10 percent of the caverns needed to be dug out.

As his crew was digging out some of this mud, an incredible thing happened. One of the men digging experienced his shovel getting stuck. It took several men to pull the tool out and once they got it, a huge explosion-like force occurred. What had happened was the crew stumbled upon an air vacuum and broken a seal. This might be common in outer space, but on Earth, it’s not exactly your everyday occurrence.

Inside the chamber there were these superb formations called anthodites that had been growing. Unfortunately, the broken seal caused the formations to cease growth, but on the plus side, there were many fine examples of the four stages of growth that had been occurring. Today, visitors can see these stages preserved within Skyline Caverns. To see these formations, tour guides take visitors behind a heavy wooden door and go through a series of small rooms that feature anthodites.

Anthodites in early stages of growth
Credit: Leigh Goessl/All rights reserved

I took this picture on New Year's Eve 2015. In this chamber's ceiling a number of small anthodites are visible. That bar you see in the lower right is the edge of a grate that covers the larger anthodites to protect them.

18-inch anthodite, the largest in Skyline Caverns
Credit: Leigh Goessl/All rights reserved

This anthodite is the longest of all found in Skyline Caverns, it is about 18 inches long. Seeing this made me wonder just how long it would have grown over time had it stayed hidden. Then I think we'd never have seen them had Dr. Amos' crew not chosen to dig in that direction.

It is a fabulous experience, especially knowing these are so rarely seen.  These formations are heavily regulated and protected by Virginia State Law.  It is estimated Skyline Caverns are about 60 million years old. Most of the caverns are not accessible to the public, only about 20 percent of Skyline is open to visitors. Fortunately, one of the sections opened allow visitors to see the beautiful anthodites.

Other places in the world where anthodites have been found include Carlsbad Caverns Timpanogos Cave National Monument, and Craighead Caverns, also located in the United States, and the Grotte de Moulis in France.

Encyclopedia of Caves
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Related Reading:

Spelunker's Dream - The Most Interesting Caves Around the World,  by Amerowolf
A Guide to Visiting Luray Caverns, Luray, Virginia, by Leigh Goessl
5 Obscure But Amazing Natural Wonders, by Wrig90

Skyline Caverns is located about 90 minutes to the west of Washington DC and conveniently located off both I-66 with close proximity to I-81.

Get Directions
10334 Stonewall Jackson Hwy, Front Royal, VA 22630, USA