Mondo Knows Facts
Beach sand is mostly broken rock
Grains are fragments of quartz, shell and coral worn down by waves over long periods Hard minerals such as quartz survive transport better than soft ones, which is why so many beaches are pale and silica-rich. White tropical sand is often ground coral and shell rather than quartz. Black sand usually means nearby volcanic rock, and green sand can come from olivine. It sits in Mondo's world geography collection, one of 200 facts that each trace back to the reference below.
Where this comes from
Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.
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More facts like this
Most of the world's coastline is not sandyRock, mud, marsh and ice make up most of the world's shorelineSpits grow where sediment drifts along the shoreWaves approaching at an angle move sand sideways until it builds a finger of land into open waterA tombolo ties an island to the shoreSand accumulates in the calmer water behind an island until a ridge connects the twoThe Great Blue Hole is a drowned caveThe circular hole in the Belize reef is a collapsed limestone cavern flooded by rising seasMangroves and mudflats absorb storm energyDense roots and soft sediment slow waves before they reach the land behindSea level is not rising evenly around the worldLand sinking or rebounding changes local sea level far more than the global average in some places
🗺️ World Geographyfact 174 of 200
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Tags: coastlines, beaches, geology
Beach sand is mostly broken rock: the short answers
- Where does this come from, and can I check it?
- Grains are fragments of quartz, shell and coral worn down by waves over long periods. The figure is taken from USGS, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
- Is this really a world geography fact?
- Yes. It sits on the World Geography shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
- What else can I read about it?
- The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.