Palagonite cliffs on Mayotte.
Palagonite is a weathering product that occurs after interaction of water with volcanic glass. This rock must have more or less the same chemical composition as basalt. Palagonite can also arise after interaction of water and molten mafian lava. This can happen, for example, when flown lava on the shore comes into contact with seawater, but also when a volcano eruption occurs underwater or under a glacier. If water comes into contact with the hot lava, hot water vapor is produced. This vapor is able to react with small melted lava particles to the light colored palagonite. This palagonite can precipitate and form a rock, the palagonite tufsteen.
Palagonite can also be very slow. When basalt is exposed to water vapor out of the air for a long time, it can be weathered with a palagonite like a thin yellow-orange layer on the rock. This process of conversion from lava to palagonite is called palagonitisation.
Palagonite Earth is a very fine and light orange yellow powder. The particle size is in the order of micrometers and is often found in the presence of larger lava particles. The color is caused by trivalent positive iron (the ferric ion) contained in the palagonite matrix. Prevent
Palagonite occurs in several places on earth. For example, in the Galapagos Islands, palagonite tufsteen occurs. In Iceland mountains of palagonite occur. These were due to the fact that at the time of the Ice Age volcano eruptions were taking place under the great glacier where Iceland was covered. See Table Mountain for more explanation about volcanic eruptions under glaciers.
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