Have you heard of Moissanite? It's a very rare mineral discovered by 19th-century chemist Henri Moissan in Arizona's Meteor Crater. At first, he thought it was diamond, but later realized it was even more rare. It's a diamond lookalike that, until the 1950s, was found naturally only in meteorites.
 
On March 4, 2025, the students of Earth to Sky Calculus launched this Moissanite pendant to the stratosphere onboard a cosmic ray research balloon. At the apex of the flight, it floated 103,655 feet above the Sierra Nevada mountains in central California.
 
The 3-carat crystal is held by a sterling silver frame with the words "I Love You" engraved on the back.
 
The students are selling space pendants to pay the helium bill for their cosmic ray ballooning program. Each one comes with a greeting card showing the jewelry in flight and telling the story of its trip to the stratosphere and back again.