What Determines A Minerals Cleavage And Hardness?

Crystal form

What determines a minerals hardness?

Hardness is determined by

the ability of one mineral to scratch another

. Federick Mohs, a German mineralogist, produced a hardness scale (table 5) using a set of ten standard minerals. The scale arranges the minerals in order of increasing hardness.

What determines a minerals cleavage?

Cleavage – The tendency of a mineral to break along flat planar surfaces as determined by

the structure of its crystal lattice

. These two-dimensional surfaces are known as cleavage planes and are caused by the alignment of weaker bonds between atoms in the crystal lattice.

What determines whether a mineral cleavage or fractures?

The strength between the atom bonds

help determine whether a mineral has cleavage or fracture because weak atom bonds is to cleavage breaking at 90 degree angles and strong bonds is to fracture which break into uneven pieces.

Why is streak more reliable for rock identification?

Streak is the color of a mineral’s powder. Streak is a more reliable property

than color because streak does not vary

. Minerals that are the same color may have a different colored streak. Many minerals, such as the quartz in the Figure 3, do not have streak.

How do you know if a rock has cleavage?

To determine the angle of cleavage,

look at the intersection of cleavage planes

. Commonly, cleavage planes will intersect at 60°, 90° (right angles), or 120°. Be cautious when you see a flat surface on a mineral – not every flat surface is a cleavage plane.

What is the softest mineral?

Talc

is the softest and diamond is the hardest. Each mineral can scratch only those below it on the scale.

What are 3 uses for minerals?

Energy minerals are used to

produce electricity, fuel for transportation, heating for homes and offices and in the manufacture of plastics

. Energy minerals include coal, oil, natural gas and uranium. Metals have a wide variety of uses.

What are the two most common elements in minerals?

Silicate

Minerals Silicon and oxygen

are the two most common elements in the Earth’s crust. Minerals that contain a combination of these two elements are called silicate minerals. Silicate minerals make up more than 90 percent of the Earth’s crust—the rest is made up of nonsilicate minerals.

Which mineral has a hardness of 6 and shows cleavage?

What are types of minerals?

There are two kinds of minerals:

macrominerals and trace minerals

. You need larger amounts of macrominerals. They include calcium, phosphorus, magnesium, sodium, potassium, chloride and sulfur. You only need small amounts of trace minerals.

What are examples of minerals?

Minerals are those elements on the earth and in foods that our bodies need to develop and function normally. Those essential for health include

calcium, phosphorus, potassium, sodium, chloride, magnesium, iron, zinc, iodine, chromium, copper, fluoride, molybdenum, manganese, and selenium

.

What mineral is not scratched by a fingernail but is scratched by a copper penny?

A mineral or other material with a higher hardness number can scratch anything with an equal or lower number. Thus, a copper penny can scratch calcite, gypsum and talc, while a fingernail can scratch only gypsum and talc. A piece of quartz can scratch fluorite but it cannot scratch

topaz

.

Why is color often an unreliable property for mineral identification?

Explanation: It is common for one mineral to be naturally found in more than one color. …

Using color alone to identify a mineral could lead to an inaccurate conclusion

. The hardness of the mineral, luster, cleavage, fracture, how it reacts to an acid, and other traits can be used to identify what the mineral is.

Why do we need to check for more than one property in mineral identification?

A mineral’s appearance helps identify it

.

However, many minerals occur in more than one color, so you would need to examine other properties as well. You might also notice how the mineral reflects light, which determines how shiny or dull it is. Most minerals reflect light in characteristic ways.

What are the 5 types of cleavage?

• Determinate.
• Indeterminate.
• Holoblastic.
• Meroblastic.