Question

write long note on..rock and minerals.?

Answer 1

Rock or Mineral?

They say that a diamond is a girl's best friend. Rubies, sapphires and other precious gemstones are also popular ways to impress a lady. Mankind has always been infatuated with rare crystals. Diamonds, in particular, have become a symbol of love and commitment. Young ladies can't wait to show off when they get a big shiny rock from the groom-to-be. But, should we really be using the word 'rock' to describe a diamond?

You may have heard the phrase 'rocks and minerals' at some point in your science schooling. The reason we say 'rocks and minerals' is because they are two different things. Rocks are not minerals, and minerals are not rocks.

As we'll soon discover, diamonds are actually minerals. Some people are under the false impression that minerals are things we eat, as in the phrase 'essential vitamins and minerals.' But really, minerals encompass a broad range of natural substances, some of which you eat, some of which you forge into tools and some of which you give to your future spouse. Let's talk about the differences between rocks and minerals so we can get all our facts straight. We'll start right now with minerals.

Minerals

A mineral is a solid, inorganic, naturally-formed substance that has a crystalline structure and specific chemical composition. I know that's a lot to take in, so let's break down this definition piece by piece.

First of all, minerals are solid and formed naturally in the earth. Natural solids can be familiar things like sand, granite, salt and wood. Our definition says that minerals are inorganic, which means that they do not consist of tissues from living things. So, that means that wood is not a mineral.

The atoms of salt are arranged in a specific lattice.

It also says that minerals have a crystalline structure. That means that the component atoms of the substance have a repeating, 3-dimensional arrangement. Above is a picture showing how the atoms of salt are arranged. Salt is also called sodium chloride because it is made of two types of atoms: sodium and chlorine. The sodium and chlorine atoms are put together in a very specific, 3-dimensional lattice that repeats over and over until you get to the end of the salt crystal. Yes, it's a crystal! I know you typically don't think of salt as being a crystal. But it is, and so is sand. Sand is just tiny chunks of quartz crystal, made by a pattern of silicon and oxygen atoms.

What about our last substance, granite? It's solid. It's formed naturally in the earth. It's inorganic. But, does it have a specific chemical composition? Does it have a regular, repeating atomic arrangement? No, granite may be made up of minerals, but it's not a mineral itself. It's a rock.

HOPE SO THIS HELPS U
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Answer 2

A rock is a solid, inorganic, naturally-formed substance without a particular atomic structure or chemical composition. It's probably easier to just remember that rocks are made up of two or more minerals. Examples of rocks include granite, limestone, marble, pumice, obsidian, sandstone, shale and slate.