Included in each Rockhound Mystery Box is a fragment of the Jack Hills Formation, an incredible specimen from the oldest stones on Earth!

The rough, sedimentary layers of the Jack Hills Formation are 3.3 billion years old, but they also contain much older zircon crystals across a range of time from 3.6 to nearly 4.4 billion years old.  

In addition to being the oldest known samples of Earth's crust, the zircons of the Jack Hills Formation also contain water and the earliest suggestions of life in the form of biogenic carbon. As the science around this topic evolves, it may push back the starting point for life on Earth by hundreds of millions of years.

Cretaceous Era turtle poop? Fossil cast of an intestinal tract? Strange ironstone nodule formation? The science is still out on just what exactly made these sideritic "coprolites"... but they certainly look like—well, we think you can tell. 💩

This specimen is a 100,000,000 year old item called a sideritic coprolite. Based on its shape and location, they are suggested to be fossilized droppings from Cretaceous Era turtles... though scientists also wonder if they could be casts of their intestines or abnormal iron formations.

These specimens come from Early Cretaceous deposits in Central Madagascar and date back 100,000,000 years.

Formed in volcanic rocks and colored violet by radiation, amethyst has an explosive origin. The traditional birthstone of February, it can be found around the world and is sought after for its beautiful purple hues.

This specimen is a single polished amethyst crystal from Rio Grande do Sul in Brazil.  An amethyst’s coloring is due to impurities in its crystal structure. The gemstone is made up primarily of quartz, a silicate that is normally a clear and colorless mineral. In some cases though, trivalent iron may be substituted for silicon. Radiation affecting the mineral helps this substitution and the internal lattice then becomes warped, causing it to refract light in such a way that the gem appears purple.

At the bottom of the sea floor, an ancient environment is home to organisms without any light from the sun. They survive off the belching sulfur of deep-sea hydrothermal vents, formations where magma heats water and spews smoke.

This awesome pin captures the wonder of the Hydrothermal Vents. Each hard enamel pin measures around 1 inch and is set with silver colored plating.

Along the bank of Lake Superior at twilight, one can find an unusual rock: sodalite-syenite. At first, this stone appears as simple granite, but under the glow of a UV flashlight, it transforms into a ball speckled with glowing orange light.

What makes sodalite so special is its fluorescence, the ability to change color under the application of UV light. The material is often found in sulfur-bearing veins, though it is debated whether the presence of sulfur contributes to the material’s fluorescence. The material has been found across the Americas, as well as in Afghanistan’s Badakhshan Province and Myanmar’s Mogok region, but its combination with syenite makes this variety of sodalite something special.

This Shining Syenite specimen comes straight from the shoreline of Lake Superior and will glow under UV light as pictured here.

When lightning strikes dry sand, the intense heat melts and fuses the silica, creating tubes of rough glass called fulgurites. The process happens quickly, often trapping molecules from the surrounding atmosphere inside the walls of the impact tube. These natural time capsules allow scientists to study the composition of ancient climates.

This specimen is a fulgurite collected in the Sahara Desert.

A classic piece for every natural history collection, Bismuth, element 83, is known best for its multicolor formations of a deep, staircase-like structure. These fractal patterns are known as hopper crystals, identifiable by their hollow step lattices. When bismuth cools it forms in a rhombohedral structure with the edges of the formation crystallizing at a much faster rate than the center of the faces. This pulls material away from the interior and leaves gaps in the structure, causing the final product to appear hollow.

This specimen is a complete bismuth crystal. They are hand cast in Colorado by a family that specializes in creating bismuth crystals for the jewelry industry.

Hematite is marked by a contrast in appearance, its dark, tar-like color nonetheless glistening with a shining luster. This compound has been used by humans for millennia, its homogenous and dense structure well-suited for toolmaking. Hematite can also be found lining cave walls in paleolithic paintings, the pigment used across the world in some of the oldest known works of art.

This specimen is a polished piece of botryoidal hematite. The rounded nodules present in the cluster owe their formation to small clumps of matter like sand the mineral formed around, giving the hematite its signature appearance.

In 1969, Apollo 11 astronauts brought rocks back to Earth from the Moon’s Sea of Tranquility. Within these stones, we found many hints towards the creation of both our moon and our own planet. Sample 10047 contained a mineral never seen by NASA geologists: Tranquillityite, named for its place of discovery.

For over 40 years, Tranquillityite was known to form only on the Moon. However, in 2011 geologists identified deposits of the mineral in Western Australia. These new samples formed in the Warakurna Large Igneous Province and are over one billion years old.

This specimen is one of those rare pieces of terrestrial Tranquillityite, recovered from Australia.