You're testing it's hardness.
You find the mineral's streak.
What you are referring to is called a streak test. It's used as an aid to mineral identification. As a mineral is drawn over the unglazed tile surface, it is reduced to a streak of dust which reveals the true color of the mineral. If no color is revealed, the streak color is called white. An amethyst crystal which appears purplish will actually have a white streak, because the streak color of the constituent quartz is white. The purplish color of amethyst is due to other reasons.
If the mineral is harder than the tile, it would damage the tile, otherwise the tile remains as it was.
color
streak
Crystal
It relative hardness, compared to others. It is relative because it does not give absolute values.
Rubbing the mineral against an unglazed ceramic tile, called a streak plate, leaves a streak of the powdered mineral. This powder reflects the true color of the mineral. It's called a streak test, and the resultant line of color is called the streak. A link can be found below to check facts and learn more.
The mark is called a streak and the color depends on what mineral you are testing.
The streak test reveals the color of a mineral in a powdered state which is used as an identifying characteristic.
Minerals can be identified by their streak, which is the color of the mineral when it is broken down into a powder. To test a mineral's streak, a streak plate (usually made of unglazed porcelain) is used. The streak is usually compared to a streak color chart, which contains the colors of a variety of minerals. To test a mineral for its streak, take a small piece of the mineral and rub it on the streak plate. The resulting powder is then compared to the streak chart to identify the mineral. Streak is an important property of minerals because it is more reliable than the external color of the mineral. External color can be altered by impurities and oxidation, but the streak of a mineral does not change. Therefore, testing a mineral's streak is an effective way of identifying it.When identifying minerals according to streak, it is important to consider the following properties: Color - the color of the powder when rubbed on the streak plate. Luster - the shine of the powder when rubbed on the streak plate. Texture - the feel of the powder when rubbed on the streak plate. Opacity - the transparency of the powder when rubbed on the streak plate.By considering these properties when testing a mineral's streak, it is possible to identify the mineral accurately and quickly.
it is hardness
You are testing the relative hardness of the mineral.
It relative hardness, compared to others. It is relative because it does not give absolute values.
Hardness
Hardness
Most likely you would be testing to see if the mineral was harder or softer than the nail.
they are testing if its real or not <3
W. D Carruthers has written: '3500-hour durability testing of commercial ceramic materials' -- subject(s): Testing, Ceramic materials
No, to tell how hard a mineral is you either have to test it or determine what mineral it is. Testing uses materials of known hardness such as a fingernail, or copper penny, or scratch plate, if the mineral is scratched by whatever you use to test it is softer. Hardness however is not based on size it will be the same for any sample of the same rock no matter what the size because its based on atomic arrangement and bond type.
Talc (a common metamorphic mineral).
will not
Rubbing the mineral against an unglazed ceramic tile, called a streak plate, leaves a streak of the powdered mineral. This powder reflects the true color of the mineral. It's called a streak test, and the resultant line of color is called the streak. A link can be found below to check facts and learn more.