What minerals can you scratch with your fingernail?
How hard is a fingernail?
Fingernails are surprisingly strong! On average, the surface of the nail is about three times harder than a human tooth and can withstand about 900 pounds of pressure per square inch. They can also resist cracking and splitting in even the most strenuous activities.
In fact, fingernails are so durable due to their flexible, fibrous nature that they can support up to 10 times the weight that can be supported by a human hair. Fingernails can even be used to help with cutting and slicing because of their innate sharpness and strength.
While fingernails aren’t as hard as a diamond or stone, they are still not to be underestimated in terms of strength and resilience.
What is the hardness of a person’s fingernail?
The hardness of a person’s fingernail depends on several factors. Generally speaking, the hardness of a person’s fingernail is due to a combination of their genetics, diet, and overall health. Properly cared-for fingernails are often described as being firm yet flexible.
It is not uncommon for the hardness of a person’s fingernail to vary from one finger to the next. Some individuals may find that their fingernails become dry, brittle, and weak over time due to environmental exposure or aging.
Other factors such as nutritional deficiencies, medical conditions, and trauma can also negatively affect the strength and condition of a person’s fingernail.
Taking good care of your fingernails is essential for keeping them hard and healthy. Keeping them clean, moisturizing them regularly, protecting them from harsh chemicals and activities, and limiting the use of nail clippers or filing can help maintain their hardness.
Additionally, maintain a balanced diet and visit your doctor regularly to ensure that you are getting all of the essential vitamins and nutrients.
What hardness can be scratched by fingernail?
As a general rule of thumb, any material with a hardness lower than 2. 5 on the Mohs scale of mineral hardness can be scratched with a fingernail. This includes materials such as talc, gypsum, calcite, and fluorite.
Talc and gypsum have the lowest hardness of 1, whereas fluorite and calcite have a hardness of 3 and 4, respectively. Generally, materials with a hardness of 2. 5 or higher are considered too tough for finger-nail scratching.
Examples of such materials include apatite, orthoclase, quartz, topaz, corundum, and diamond – the hardest mineral on the Mohs scale with a hardness value of 10. Therefore, if an item cannot be scratched with a fingernail, it is possibly composed of the latter minerals.
How hard is a mineral you can scratch with your fingernail?
Scratching a mineral with your fingernail can be quite difficult. Depending on the hardness of the mineral, it may require a great deal of pressure to make a scratch. Most softer minerals can be scratched with pressure from your fingernail, but harder minerals will require a tool like a steel knife, or even something harder like a diamond.
Knowing the hardness of the mineral in question is the best way to determine how difficult it will be to scratch.
Are fingernails harder than gold?
No, fingernails are not harder than gold. The hardness of a material is measured on the Mohs scale of mineral hardness, which ranges from 1-10. Fingernails rank 2. 5-3 on the hardness scale, while gold ranks at 2.
5-3 as well. As you can see, the two materials have similar levels of hardness. However, gold is much more malleable and ductile than fingernails, meaning it can be hammered into thin sheets and formed into various shapes.
Are teeth stronger than diamond?
No, teeth are not stronger than diamonds. Diamonds are the hardest natural substance known to man, rated at a 10 on the Mohs scale of mineral hardness. This means that diamonds are four times harder than the next toughest natural mineral, which is corundum (9 on the Mohs scale).
Teeth, however, are only between 5. 5 and 7 on the Mohs scale, making them far less durable than diamonds.
The hardness of teeth comes from their enamel; this hard outer layer is strong enough to protect the softer and more vulnerable layers beneath it but is not as durable as a diamond. If the teeth come into contact with too many acidic materials, the enamel can be damaged and the vulnerable layers can be exposed.
This can lead to cavities and other mouth infections, which is why it is so important to follow an oral hygiene routine that includes brushing your teeth at least twice a day, flossing, and visiting a dentist at least twice a year for regular check-ups.
Do fingernails get stronger as you age?
No, fingernails do not get stronger as you age. However, they tend to be harder and more resistant to breakage and splitting. This is because as you age, your nails become dryer, more brittle, and more prone to cracking, peeling, and splitting due to a decrease in the production of natural oils and proteins.
Additionally, your nails are composed of keratin, which is a protein that becomes more brittle with age. The decrease in natural oils and protein combined with the brittleness of keratin cause your nails to become less flexible and more prone to breaking.
To keep your nails healthy, try to routinely moisturize them with a cream or oil and wear gloves to prevent them from breaking.
Which mineral is harder than the fingernail?
The Mohs Hardness Scale is used to measure the hardness of a mineral. Minerals are rated on a scale of 1 (softest) to 10 (hardest). Fingernails typically rate a 2. 5 on the Mohs Hardness Scale, making them one of the softer materials.
Any mineral that is rated higher than a 2. 5 on this scale is harder than a fingernail. Some examples of minerals that are harder than fingernails are:
What minerals can you scratch with your fingernail?
What is a Mineral?
Not all minerals are perfect and shiny, as a matter of a fact most of them look like rocks but they aren�t. So you may be asking, what�s the difference between a rock and a mineral? Well there are four questions you must answer to tell if something is a mineral. First, Does it have a crystalline structure? Basically this means that it has a repeating inner structure that often reflects the shape of a crystal. Then, Is it a solid? Minerals can not be either a liquid or a gas only solid. Is it formed it nature? Man- made minerals are not minerals. Is it in organic? Meaning it is not made of living things. If you answered yes to all of these questions it is a mineral.
History of Talc
Talc was first discovered by a geologist in 1546. The name talc comes form the Arabic language but is also known by several other names such as steatite, soapstone, potstone and French chalk. It is believed by geologists that Talc is formed over millions of years, cave men 15,000 years ago used it as an ingredient in their paints and it is also believed that back in the times of the tang dynasty it was used in glazed pottery.
Mohs Hardness Scale
Mohs hardness scale is a scale that identifies the hardness of a mineral. It rates the mineral�s hardness from one to ten, ten being the hardest.
- Talc
- Gypsum
- Calcite
- Fluorite
- Apatite
- Orthoclase
- Quartz
- Topaz
- Corundum
- Diamond
A minerals rating on the hardness scale is determined by a scratch test. For example the diamond is the hardest mineral because no other mineral on the scale is able to scratch it. Basically if two minerals can both scratch each other they are of the same hardness but if one can only scratch the other that one will be higher on the scale. Since Fluorite is a 4 on the scale it means that fluorite can scratch all the minerals below it but not be scratched by them. Also if a penny can scratch a mineral it rates a 3, a fingernail is 2.5, knife blade 5.5, glass 5.5 and steel file 6.5. Talc rates a one on the scale meaning that it is the softest mineral and can be scratched by just about anything.
Who is Moh? The Mohs hardness scale was name after Friedrich Moh, a German mineralogist of the seventeenth century. In 1822 he this method of mineral hardness and scratch resistance.
Talc is usually white to a pale of dark green color, gray or even brown. If the specimen is impure meaning that something has caused a chemical reaction with inside it the mineral can turn bright red or pink. The color is not the best way to identify a mineral because it can be changed by weathering and is not an accurate source of information.
The fine powder or mark made by a mineral when scratched or rubbed against a harder surface. The streak of a mineral is the color of the mineral in powder form. This can be determined by dragging the mineral across an unpolished tile. The color of a mineral’s streak can not be changed; weathering has no effect on the streak. Talc has a white streak no matter what color it is on the out side.
Luster is the way the surface of a mineral reflects light. There are three different ways to classify a minerals luster. Metallic is when a mineral is very shiny, non-metallic is when the mineral is kind of dull and does shine at all. Right in between the tow you have sub-metallic, which shines a little bit but is still dull. The mineral talc has a non metallic luster, it is often described a pearly of greasy
Cleavage is the splitting along the definite crystalline structure creating smooth surfaces, fracture is the tendency a mineral has to break along flat surfaces. Talc has a perfect cleavage and fracture because it is so soft that it breaks so easily. Notice in the picture above the little cracks in the mineral show how easily it chips off.
The formula for density is D=M/V. What this basically means is that you Find the Mass using a triple beam balance and divide it by the volume using a graduated cylinder. The mass is measured in grams. The volume is measured in ML, a good tip to use when measuring volume is to first fill it up to the 100ML mark then drop the mineral in. Once you get an accurate reading subtract 100ML from that to give you the minerals volume. Talc�s volume is 2.82.
Talc can be used in different cosmetic products and in the process of making pottery when ground up into a powder but it uses are constantly expanding.
Mohs Hardness Test
Determining the hardness of an unknown rock or mineral is often very useful in the identification process. Hardness is a measure of a mineral’s resistance to abrasion and is measured against a standard scale — Mohs Scale of Hardness. Mohs Scale was named after Frederick Mohs (1773-1839), a German minerologist. It consists of 10 fairly common minerals (except for the diamond) of known hardness which are numerically ordered from the softest (1) to the hardest (10). They are:
.1. Talc (H=1) | .2. Gypsum (H=2) | .3. Calcite (H=3) | .4. Fluorite (H=4) | .5. Apatite (H=5) |
.6. Orthoclase (H=6) | .7. Quartz (H=7) | .8. Topaz (H=8) | .9. Corundum (H=9) | .10. Diamond (H=10) |
As common sense dictates, Mohs Scale is based on the fact that a harder material will scratch a softer one. By using a simple scratch test, you can determine the relative hardness of an unknown mineral.
How to Perform the Test
- Select a fresh, clean surface on the specimen to be tested.
- Hold the specimen firmly and attempt to scratch it with the point of an object of known hardness. In this example, we use a sharp quartz (H=7) crystal .
- Press the point of the crystal firmly against the surface of the unidentified specimen.
- If the «tool» (in this case the quartz crystal) is harder, you should feel a definite «bite» into the surface of the specimen.
- Look for an etched line. It is a good idea to rub the observed line with your finger to ensure that it is actually etched into the surface of the specimen. In this case, the crystal left a deep, definite scratch in the surface. Because the specimen was scratched by the quartz crystal, we know its hardness is less than that of the quartz, less than H=7.
- If there is any question about the result of the test, repeat it being sure to use a sharp point and a fresh surface.
«Tools» for Testing Hardness
Believe it or not, most people do not normally carry around samples of the 10 minerals on the Mohs Scale! However, there are several simple «tools» people often have with them that can be useful in determining the relative hardness of an unknown mineral specimen.
Your fingernail has a hardenss of 2.5. If you can scratch the surface of an unknown specimen with it, you will immediately know that its hardness is less than 2.5. In other words, it is slightly harder than gypsum (H=2) but softer than calcite (H=3).
A penny has a hardness of 3.0 — slightly harder than your fingernail. So, if you can’t scratch the specimen with your fingernail (H=2.5), but a penny does the job, you immediately know that it is at least as hard as calcite (H=3).
The steel blade of the average knife usually has a hardness of about 5.5. If a penny does not scratch your unknown specimen but the knife blade does, then you can correctly conclude that it is harder than calcite (H=3) but softer than orthoclase (H=6).
Example: You select one of the minerals from Mohs Scale that looks like the one pictured here and find that it can be scratched by the knife (H=5.5) but not by the penny (H=3). Therefore, you are able to conclude that the specimen has a relative hardness between 3.0 and 5.5. The minerals from Mohs Scale that fall into that relative hardness range are calcite (H=3), fluorite (H=4) and apatite (H=5). By using your powers of observation and your knowledge of other physical characteristics of minerals such as crystalline structure, color, streak etc. you are able to conclude that your sample is calcite !
Get the idea? Easy isn’t it? If you’d like a set of the Mohs Scale minerals for your personal use or for your classroom, check out our card mounted or boxed sets of specimens or our Hardness Testing Kit.
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