Gem belching volcano

Hawaii's Volcano Is Literally Erupting Gems
Trevor Nace , Contributor
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Small olivine crystals on the Big Island of Hawaii.

Hawaii's Kilauea volcano has been fiercely erupting for well over a month. Now, residents are finding little green gems that have fallen out of the sky during Kilauea's eruption.

The green gems are olivine crystals, a common mineral found in Hawaii's lava. At jewelry quality, the mineral is called peridot. As the volcano erupts, it blasts apart molten lava, allowing for green olivine minerals to be separated from the rest of the melt and fall as tiny gemstones.

Lava spews in Kilauea's East Rift Zone on May 23, 2018 in Pahoa, Hawaii, amid eruptions from the Kilauea volcano. - Kilauea is one of the most active volcanoes in the world and one of five on the Big Island of Hawaii. It erupted May 3, forcing the evacuation of 2,000 people from their homes located on the mountain. Scientists believe volcanic activity may be a precursor to a major eruption, similar to one that occurred on the island in the mid-1920s. (RONIT FAHL/AFP/Getty Images)

There are several places in Hawaii that the beaches are a green color, this is due to a high concentration of olivine that has weathered out of the mafic lava (basalt). In fact, olivine is one of the most common minerals below Earth's surface but it is quite hard to find it separated from the parent rock and even harder to find it of gem quality.

Papakolea Beach with green sand, Big Island Hawaii

Olivine is so common that experts estimate over 50 percent of Earth's upper mantle is composed of olivine or variations of the mineral. While it is a common mineral, little crystals of olivine falling out of the sky are quite unusual.