Cosmic Geology
When we think of geology, we think of magma chambers, tectonic pressure, and sedimentary riverbeds. But the rarest and arguably most fascinating rocks on earth weren't formed on earth at all.
Every year, thousands of tons of cosmic debris enter Earth's atmosphere. Most burn up as shooting stars. But occasionally, enormous chunks of asteroids survive the fiery descent. These impacts create two categories of highly collectible lapidary materials: Meteorites (the space rocks themselves) and Tektites (impact glass created by the explosion).
Pallasite Meteorites: Space Peridot!
Of all meteorites, Pallasites are the holy grail for gemologists. They represent less than 1% of all known meteorites.
A Pallasite is a stony-iron meteorite that is essentially an iron-nickel matrix packed full of translucent, golden-green Olivine crystals (the gemstone variety of olivine is known as Peridot). When sliced extremely thin and polished by a master lapidary, light shines directly through the extraterrestrial green crystals trapped in the metallic alien web.
Pallasites are thought to be the core-mantle boundary of destroyed ancient planets or massive asteroids from the early formation of our solar system!
Cosmic gemstones require extreme care due to atmospheric rusting.
Tektites: The Splash of the Gods
When a meteorite of unimaginable size strikes the Earth, it doesn't just make a crater. The kinetic energy is converted into heat so intense that it instantaneously melts the sand and bedrock. This explosive impact vaporizes the rock and blasts liquid magma out into the vacuum of the upper atmosphere.
As the liquid falls back down to Earth, it cools extremely rapidly in the air, aerodynamically shaping itself into dumbbells, teardrops, and buttons. This unique impact glass is called a Tektite.
1. Moldavite
Moldavite is the most famous tektite. 15 million years ago, an asteroid struck southern Germany, creating the Ries crater. The resulting tektites rained down over the Czech Republic. Moldavite is distinctly olive-green, deeply textured, and heavily sought after by crystal healers and collectors. Due to high demand and depleting mines, real Moldavite is extremely expensive and heavily faked using green bottle glass from China.
2. Libyan Desert Glass
29 million years ago, a cosmic airburst (a comet or asteroid exploding incredibly close to the ground, like the Tunguska event but far larger) occurred over the Sahara desert. It melted the pure quartz sands of Egypt into massive chunks of pale, sun-yellow glass. When King Tutankhamun's tomb was opened, the spectacular yellow scarab beetle in his burial pectoral was carved not from topaz, but from Libyan Desert Glass!
3. Indochinites
The most common tektites are completely black, obsidian-like glass found across Southeast Asia and Australia. Originating from an impact around 800,000 years ago, these are highly affordable and display incredible aerodynamic flight mechanisms.
How to Collect and Care for Them
If you acquire an iron meteorite or a Pallasite slice, remember that they are composed of iron and nickel. In the vacuum of space, iron doesn't rust. In the humid atmosphere of Earth, they rust aggressively!
- Keep iron meteorites in extremely dry environments (use silica gel packets).
- Coat polished slices in specialized gun oil or microcrystalline wax to seal out oxygen.
- Tektites (like Moldavite) are just glass. They do not rust, but they will chip easily if dropped.
Owning a piece of the cosmos bridges the gap between astronomy and lapidary, allowing you to hold a 4.5-billion-year-old remnant of the solar system's birth in the palm of your hand.