Pumice facts for kids
Pumice is a very light and airy rock that comes from volcanoes. It's like a frozen foam made from lava, which is super hot, melted rock.
Pumice forms when hot, bubbly lava shoots out of a volcano. As it flies through the air, it cools down super fast. The quick cooling and drop in pressure make lots of tiny bubbles get trapped inside the rock. Imagine opening a fizzy drink – bubbles appear because the pressure drops! That's kind of what happens with lava, and then the bubbles get stuck as the lava hardens into pumice.
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Where is Pumice Found?
Pumice can be found all over the world, both from volcanoes on land and under the sea. Sometimes, pieces of pumice float on the ocean and travel far with the currents. Since pumice is made by explosive volcanoes, you'll find it in places where volcanoes are active. People dig for pumice in these areas and then transport it to other places. In 2011, the countries that produced the most pumice were Italy and Turkey.
Pumice in Asia
Asia has big amounts of pumice in countries like Afghanistan, Indonesia, Japan, Syria, Iran, and eastern Russia. The Kamchatka Peninsula in Russia, which has 19 active volcanoes, is a major source. This area is part of the "Pacific volcanic belt" where many volcanoes are found.
A famous eruption that produced a lot of pumice was Mount Pinatubo in the Philippines in 1991. It threw out so much ash and pumice that it filled deep valleys nearby. Another well-known volcano, Krakatoa, erupted in 1883 and covered miles of the sea with floating pumice, some of it rising 1.5 meters (about 5 feet) above the water!
Pumice in Europe
Europe is the biggest producer of pumice, with large amounts found in Italy, Turkey, Greece, Hungary, and Iceland. Italy leads the way because it has many active volcanoes. For example, the island of Lipari in Italy is almost entirely made of volcanic rock, including lots of pumice.
Pumice in North America
You can find pumice across North America, including the Caribbean Islands. In the United States, pumice is dug up in states like Nevada, Oregon, Idaho, Arizona, California, New Mexico, and Kansas. Idaho is known for its high-quality, bright pumice.
About 7,700 years ago, a huge volcano called Mount Mazama in Oregon erupted. It left behind 300 feet (about 90 meters) of pumice and ash. The eruption was so big that the volcano collapsed, forming a large bowl-shaped area now known as Crater Lake.
Pumice in South America
Chile is one of the world's top producers of pumice. In 2011, the Puyehue-Cordón Caulle volcanoes in the Andes mountains erupted, covering parts of Chile and Argentina with ash and pumice.
Pumice in Africa and Australia
Some pumice deposits are found in Kenya, Ethiopia, and Tanzania in Africa.
In 2012, the Havre Seamount volcano under the ocean near New Zealand had the biggest deep-ocean eruption ever known. Huge pieces of pumice floated on the Pacific Ocean, forming thick layers up to 5 meters (16 feet) deep. Much of this floating pumice ended up on the coast of New Zealand and the Polynesia islands.
How is Pumice Mined?
Mining pumice is quite gentle on the environment compared to other types of mining. This is because pumice is usually found on the surface of the Earth in loose piles.
Workers use machines like bulldozers and power shovels to dig up the pumice. They remove the top layer of soil to get to the purer pumice underneath. Special screens are used to filter out any dirt or unwanted rocks. Since pumice is already loose, they don't need to use explosives. After mining, the pumice is often crushed into different sizes, from large chunks to very fine powder, depending on what it will be used for.
What is Pumice Used For?
Pumice is light, full of holes, and a bit rough, which makes it useful for many things. People have used it for thousands of years in building, for personal care, and even in early medicine. It's also used as a scrubbing material in things like polishes, pencil erasers, and to make stone-washed jeans.
Today, there's a lot of demand for pumice. It's used for filtering water, cleaning up chemical spills, making cement, in gardening, and even for pets!
Pumice in Personal Care
Pumice has been used for personal care for a very long time. Because it's a bit rough, it can be used as a powder or a stone to remove unwanted hair or dead skin.
In ancient Egypt, people used pumice stones to remove body hair. In ancient Rome, powdered pumice was used to whiten teeth. People in ancient China used pumice stones to keep their nails neat and to remove hard skin (calluses) from their feet.
Today, many of these uses are still common. Pumice is widely used as a skin exfoliant to make skin smoother. "Pumice stones" are popular in beauty salons during pedicures to remove dry skin and calluses from feet. Fine pumice powder is also added to some toothpastes to help whiten teeth and remove dental plaque. You might also find pumice in heavy-duty hand cleaners, like "lava soap," to help scrub away tough dirt.
Pumice in Gardening
Good soil needs to hold enough water and nutrients, but also be loose enough for air to move through easily. Plant roots need a constant supply of carbon dioxide and oxygen.
Pumice helps improve soil because its tiny holes allow water and gases to move easily. These holes can also store nutrients for plants. Since pumice is a rock, it doesn't break down or get squashed over time. Another good thing is that it doesn't attract fungi or insects.
Adding pumice to soil makes it easier to dig and helps with drainage. It's great for growing plants like cacti and succulents because it helps sandy soils hold more water and makes heavy clay soils lighter so air and water can move better. Pumice is also pH neutral, meaning it's not acidic or alkaline, which is good for most plants. In 2011, about 16% of the pumice mined in the United States was used for gardening.
Pumice in Construction
Pumice is often used to make lightweight concrete and special blocks called cinder blocks. The air-filled spaces in pumice make it a good insulator, helping to keep buildings warm or cool.
A fine type of pumice called pozzolan is mixed with lime to create a light, smooth concrete. The ancient Romans used this type of concrete thousands of years ago! They used it to build amazing structures like the huge dome of the Pantheon. They even added more pumice to the concrete for the higher parts of the dome to make it lighter. It was also used to build many aqueducts, which were like bridges that carried water. Today, pumice is still a very important material for making concrete, especially in areas near where it's found.
Images for kids
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Kutkhiny Baty is a cool rock formation made of pumice in Russia.
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Pumice soap bars, often used for scrubbing.
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A solid bar of pumice stone, commonly used for personal care.
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These rocks from the Bishop tuff show pumice on the left.
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This picture shows how light pumice is – a piece is easily held up by a rolled-up U.S. 20-dollar bill.
See also
In Spanish: Pumita para niños
