During Curiosity’s more than ten-year exploration of Mars, the surface has shown so-called “fracture halos” – cracks surrounded by lighter rock, which could be an indication of the presence of opals.

According to a study by Arizona State University, this vast network of cracks was likely one of the last – if not the very last – water-rich place in Gale Crater. Opal consists of amorphous hydrous silica. The gemstone is created when water rich in silica settles in cracks and crevices.

The researchers in Arizona have used new methods to go through archived data from Curiosity’s spectrometer “Dan” (Dynamic Albedo of Neutrons), an instrument for analyzing the rock samples collected by the rover. The review confirms that the stone in “fracture halos” has an opal-rich composition. It writes the university in a press release.

Opals contain water

The cracks have a large geographical spread, but the investigation shows that the composition of the material consistently has striking similarities – and according to the researchers, they are likely to be chock full of opals.

NASA’s great interest in the gemstone is about the possibility of extracting water. Because the water content of opal is usually 6-10 percent of the stone’s weight, but can be up to 21 percent. Extraction is as simple as crushing the material and adding heat.

The researchers believe that one meter of the material could yield 5.6 liters of water. In other words, the systems of cracks can be an interesting place for colonizers.