As molten rock flies through the air, it forms into substances known as Pele’s hair and tears.
So-called Pele’s hair, named after the Goddess of Fire who inhabits Kilauea volcano, is vitrified lava, or threads of glass, that looks very much like golden hair. Millimeters in thickness but sometimes very long, they are lightweight and carried by the wind. Strands of the “hair” blown in the wind collect in clumps on the ground or in vegetation. The fine threads are formed when bubbles of lava burst, blown hot into the wind to stretch and cool. The substance can be found in relation to lava fountains in Hawaii and in Iceland where it’s also called Nornahár meaning Witch’s Hair.
Like asbestos and fiberglass (which is what this, essentially, is), these fibers are also hazardous if inhaled and irritating if rubbed into eyes or skin.
The current eruption of Kilauea is producing “hair”. From HAWAIIAN VOLCANO OBSERVATORY STATUS REPORT
U.S. Geological Survey. Tuesday, May 29, 2018, 7:45 AM HST:
Pele’s hair and other lightweight volcanic glass from high fountaining of Fissure 8 are being transported downwind and falling to the west of the fissure. On Monday night, there were reports of Pele’s hair falling in Pāhoa. Residents are urged to minimize exposure to these volcanic particles, which can cause skin and eye irritation similar to volcanic ash.
Drops of molten lava in a spray instantly cool to form tapered black drops of glass called achneliths or Pele’s tears. The “tear” may often be found at the end of a “hair” as the tail is spun from the trail of liquid in motion. Glass has no crystal structure as it solidifies too quickly. Because of the quick freeze, geologists can use the hair and tears to tell something about the magma from the eruption. The shape of the tears can provide an indication of the velocity of the eruption.
As the blobs of lava get bigger, the tears become “bombs” which can damage structures and even cause injury and death as the outside cools but the core remains molten.
UPDATE 28-November 2022 Pele’s hair may be produced from Mauna Loa eruption
Mauna Loa is erupting for the first time in 38 years. The news came with a notice from the Hawaiian Volcano Observatory that while the lava currently is localized and does not pose a threat, the wind may create and carry Pele’s hair downwind along with gases and ash.