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stone

Primary Information
Secondary Information

Definition

In geology, a stone is any naturally occurring, solid mass that is made up of one or more minerals. Minerals are the building blocks of rocks, and they come in all shapes and sizes. The way in which a rock is formed determines its type.

There are three main types of rocks: igneous, sedimentary, and metamorphic.

  • Igneous rocks are formed from the cooling and solidification of magma or lava.
  • Sedimentary rocks are formed from the accumulation of sediments, such as sand, mud, and gravel.
  • Metamorphic rocks are formed when existing rocks are subjected to heat, pressure, or chemical changes.

The properties of a stone, such as its hardness, colour, and texture, are determined by the minerals that it is made up of.

Stones have been used by humans for centuries for a variety of purposes, such as building materials, jewellery, and tools.

How can the word be used?

The path was lined with stony ground.

stone

Different forms of the word

Noun: stone (plural: stones).

Adjective: stony.

Verb: to stone.

Etymology

The word "stone" comes from the Old English word "stān", which means "hard rock". It was first used in English in the 7th century.

The word "stony" means "made of stone" or "like stone".

The word "to stone" means "to pelt with stones".

Question

What stones is mentioned in the definition?

AQA Science Exam Question and Answer

Question:

Explain the formation of sedimentary rocks, focusing on the role of compaction and cementation. Discuss how different types of sediment lead to the formation of various sedimentary rocks, including examples of rocks that can form through these processes.

Answer:

Sedimentary rocks are formed through the accumulation, compaction, and cementation of sediments over long periods. The process begins with the weathering and erosion of pre-existing rocks, leading to the creation of loose particles such as sand, silt, and clay. These sediments are transported by natural agents like water, wind, or ice and eventually settle in layers.

Compaction occurs when the weight of overlying sediments compresses those below, reducing pore space. This pressure causes the particles to come closer together, expelling water and air. Cementation follows, where mineral-rich water infiltrates the sediments and precipitates minerals between the particles, acting like a natural glue that binds them together.

Different types of sediments yield distinct sedimentary rocks. Sand grains, when compacted and cemented, form sandstone. Clay particles produce shale when similarly processed. Limestone forms from calcium-rich marine organisms' remains, accumulating over time and undergoing compaction and cementation.

Ultimately, sedimentary rocks provide valuable insights into Earth's history, as they record environmental conditions and processes of the past. Understanding the formation of sedimentary rocks sheds light on Earth's dynamic processes and helps us interpret the geological history of various regions.