valuable, because metamorphic minerals and rocks have economic value. For example, slate and marble are building materials, garnets are used as gemstones and abrasives, talc is used in cosmetics, paints, and lubricants, and asbestos is used for insulation and fireproofing.

Explanation: Metamorphic rocks, like slate and marble, are formed from heat and pressure. This happens under the Earth’s surface and the minerals in the rocks are chemically changed. It can also occur close to volcanoes, where underground magma can cause the heating.

Common metamorphic rocks include phyllite, schist, gneiss, quartzite and marble.

Metamorphic rocks are divided into two categories- Foliates and Non-foliates. Foliates are composed of large amounts of micas and chlorites. These minerals have very distinct cleavage. Foliated metamorphic rocks will split along cleavage lines that are parallel to the minerals that make up the rock.

Look at the texture of the rocks: some metamorphic rocks are layered and others are made up of grains. Quartzite and marble are granular. They do not have layers of material. Schist is a layered metamorphic rock.

Typical low-grade metamorphic minerals are albite, muscovite, chlorite, actinolite and talc. Slate is an extremely dense, fine-grained metamorphic rock form under low-grade regional metamorphism emerged from pelitic sedimentary rocks such as shales and fine-grained tuffs (Table 6.1).

Igneous rocks form from molten rock, and rarely have fossils in them. Metamorphic rocks have been put under great pressure, heated, squashed or stretched, and fossils do not usually survive these extreme conditions. Generally it is only sedimentary rocks that contain fossils.

Metamorphic rocks are almost always harder than sedimentary because they have gone many processe . They are generally as hard and sometimes harder than igneous rocks. They form the roots of many mountain chains and are exposed to the surface after the softer outer layers of rocks are eroded away.

Sedimentary rocks

Metamorphic rocks

The strongest rock in the world is diabase, followed closely by other fine-grained igneous rocks and quartzite. Diabase is strongest in compression, tension, and shear stress. If mineral hardness is the determining factor of strength then diamond is technically the strongest rock in the world.

talc

Scientists have calculated that wurtzite boron nitride and lonsdaleite (hexagonal diamond) both have greater indentation strengths than diamond. Source: English Wikipedia. (PhysOrg.com) — Currently, diamond is regarded to be the hardest known material in the world.

Diamond is harder than obsidian, as obsidian is a form of volcanic glass. Obsidian has a hardness of 5 to 5.5 on the mineral hardness scale, whereas diamonds have a hardness of 10.

As an example, you can scratch steel with a diamond, but you can easily shatter a diamond with a hammer. The diamond is hard, the hammer is strong. This makes the diamond incredibly hard and is why it is able to scratch any other material. Steel, on the other hand, has an ionic structure.

Cutting edge Obsidian – a type of volcanic glass – can produce cutting edges many times finer than even the best steel scalpels. At 30 angstroms – a unit of measurement equal to one hundred millionth of a centimeter – an obsidian scalpel can rival diamond in the fineness of its edge.

It doesn’t seem unreasonable to wonder whether diamonds are bulletproof, since diamond is the world’s hardest natural material. Diamonds are not however bulletproof in general, as while they are hard, they are not particularly tough and their brittleness will cause them to shatter when struck by a bullet.

A diamond is the hardest material on the earth and the most expensive gemstone as well. Diamonds are not rare but high-quality diamonds that can be used in the jewelry are rare. In addition, the size and quality of the diamond also plays a major role on the price. These are the reasons why diamonds are so expensive.

You bet it can! yes, diamond can be broken easily by the hammer. look diamond is strong when it comes to its structure and bond, but when with sure force and specific point it has been hit, it will be broken.

It’s harder than diamond and substantially rarer, “making its value extremely high,” according to the publication. …

The World’s Strongest Stuff

• Diamond. Unmatched in its ability to resist being scratched, this much-loved gemstone ranks the highest in terms of hardness.
• Graphene.
• Spider silk.
• Carbon/carbon composite.
• Silicon carbide.
• Nickel-based super-alloys.

Diamond