If Tranquillityite has an otherworldly sound to you, you’re onto something! The mineral was first discovered during Apollo 11 on the lunar surface, a piece of the basaltic Sea of Tranquility.

Named for its discovery site, Tranquillityite was thought to be a solely lunar mineral but was later discovered on Earth. Known to at least six locations in Western Australia, Tranquillityite was the last lunar mineral that was thought to be exclusive to the Moon until its discovery on Earth in 2011.

This specimen is a rare piece of Tranquillityite recovered from Australia. It measures between 0.5"-1" and is encased safely within an acrylic gem jar.

Each specimen ships with a classic, glass-topped display box along with an informational photo card which serves as statement of authenticity.

In 1969, the crew of the Apollo 11 mission returned to Earth with a collection of moon rocks. These stones, pulled from the landing site in the Mare Tranquillitatis, held within them secrets of the Moon and our solar system at large. Hidden inside sample 10047 was a never-before-seen mineral, soon named after its location of collection: Tranquillityite.

Stones brought back from the Moon were of great interest to both the public and the scientific community alike. With so much excitement around their collection, the rocks were quickly subjected to intense study, with every aspect of them being analyzed as closely as possible.

For over 40 years, the mineral was thought to only occur on the Moon with the few terrestrial appearances of it coming from meteorites. This all changed in 2011, when deposits of Tranquillityite were found in several sites around western Australia. Though incredibly rare, it is now known that Tranquillityite does form naturally on planet Earth. These terrestrial samples formed over a billion years ago, alongside the Warakurna Large Igneous Province.

Looking at Tranquillityite’s unique properties, it’s understandable why it was believed to be only found on the Moon. The mineral appears as long, thin crystals called laths surrounded by a base of plagioclase, pyroxene, olivine, and ilmenite. Rich in zirconium, it is often found alongside similar minerals like baddeleyite and phosphorous-rich minerals like apatite. Along with pyroxferroite and armalcolite, Tranquillityite was one of three minerals discovered during Apollo 11 that had never been found on Earth.

A silica-based mineral, Tranquillityite also has high levels of iron, titanium, and yttrium. The iron present sometimes colors the mineral a dusky red. Samples from Apollo 12 show a uniform composition to the original material discovered. Since its discovery on the Moon, Tranquillityite has also been found in previously uncovered lunar meteorites. In 2010, Martian meteorite NWA 856 was also found to contain Tranquillityite. 

Like its lunar counterpart, terrestrial Tranquillityite occurs as thin lath crystals and is found alongside baddeleyite, zirconolite, apatite, and ilmenite. Dating of the Australian samples suggests that they formed alongside the Warakurna large igneous province, 1.07 billion years ago.

The Mare Tranquillitatis, or Sea of Tranquillity, has been gazed upon throughout human history. Its name was given by the Italian astronomers Francesco Grimaldi and Giovanni Riccioli in the 1651 folio Almagestum novum.

The maria were once thought to represent ancient dried seas, though our modern understanding tells us that it was not water that flowed in these basins but lava. Basaltic rocks were formed as the lava cooled and millions of years later the maria are visible due to the dark basalts. Mare Tranquillitatis is comparable in size to the Black Sea and contains material over 3.6 billion years old.