Geological “fake news”: the reports of precious stones falling from the sky following the eruption of the Kilauea Volcano are not consistent with the facts

For over a month now, Hawaii’s Kilauea Volcano is erupting, spewing lava and ashes, with extensive media coverage focused mainly on the destruction it has brought upon the residents of the region. Recently, however, a new story came into the spotlight regarding the volcano, which gives the eruption a silver lining. Has Kilauea started to redeem the destruction and heartache of its own doing by emitting gemstones into the sky?

Two recent tweets by Hawaiian residents excitedly claim that “it is literally raining gemstones,” after being emitted from the depths of the Earth during the recent volcanic eruptions. The gemstone in question is made of clear olivine, a beautiful olive-green mineral which, when it is of high quality, olivine is considered to be a semi-precious stone called peridot. The enviable pictures posted together with those tweets quickly went viral, and many news websites around the world were quick to publish the exciting news piece.

 

 

Notwithstanding the media frenzy, a number of volcanologists (geologists who are volcano experts) from Hawaii are trying to curb the enthusiasm. They claim that the last Kilauea eruption could not have emitted such crystals and that these are probably crystals that have crumbled from volcanic rocks that formed during more ancient eruptions.

Comprised of silicon, oxygen, iron, and magnesium, olivine is one of the most ubiquitous minerals on Earth, and one of the main components of basalt rocks. It was also found in the basalt rocks extruded during the last Kilauea eruption, but only in the form of tiny crystals, up to one or two millimeters in size. Olivine usually begins crystalizing deep in the earth before rising to the surface inside the liquid magma, and only under certain conditions will it grow in the magma to reach a significant size. According to geologists, this was not the case in the most recent eruption. 

 

ההתפרצות האחרונה לא הייתה יכולה לפלוט גבישי אוליבין מהסוג הזה. הר הגעש קילוואה | צילום: ויקיפדיה, Sanjay Acharya
The last eruption could not have emitted this kind of olivine crystals. Volcano Kilauea | Photograph: Wikipedia, Sanjay Acharya

Large olivine crystals are relatively common in Hawaii and even comprise the sand in some of its beaches. They originate from basalt rocks that formed from lava emitted in more ancient eruptions, whose physical and chemical conditions enabled the slow crystallization necessary for the formation of large crystals. Volcanic eruptions, even when occurring within the same volcanic crater, can differ in lava composition. In many cases, the volcano rising from the surface is just an expression of a weak point in the Earth's crust, and the lava flowing through it can actually come from a different region within the mantle at each eruption.

The current news reports about gemstones shower resulting from the volcanic eruption are multiplying and receiving extensive media attention, while the opposing opinions of scientists, substantiated by studies of the matter at hand, are brushed aside. This is an interesting case in which the harmless “sparkle” of the story, combined with the tempting potential to attract more readers to the news websites, trample the scientific facts. 

 

Translated by Elee Shimshoni

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