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Those minerals that are harder than the unglazed porcelain streak plate will scratch it rather than leave a streak.
Topaz (8), corundum (9), and diamond (10).
it is used to test streak, for rocks and minerals
by strecting it on a streak plate
You can determine the streak of a mineral whose Mohs scale is higher than the streak plate by either filing or crushing with a hammer before rubbing the sample on a streak plate.
Hematite, gold, feldspar or magnetite
Streak color is determined by scraping the mineral across a a streak plate, (which is made of unglazed porcelain), and then observing the color of the streak, which is left on the plate. Note that some minerals do not leave a streak, as they are too hard. Thus, it is important to learn other identification methods, to use in conjunction with streak color, in order to identify minerals.
Some minerals are harder than a streak plate and will therefore leave no streak or the powder of the ceramic streak plate.
Those minerals that are harder than the unglazed porcelain streak plate will scratch it rather than leave a streak.
A streak plate has hardness of 7 on the Mohs scale, so harder minerals will not leave a streak. Diamond has a hardness of 10 and corundum is 9 - so neither will leave a streak.
The streak of a mineral refers to the color left on a streak plate after rubbing a mineral across its surface. A streak plate can be as simple as the unglazed side of a porcelain tile. The streak is the mineral in a powdered form from abrasion with the hard, slightly textured surface of the unglazed porcelain streak plate. The streak color may differ from the color observed in a specimen. The streak is used as an aid in the identification of minerals.
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.
Topaz (8), corundum (9), and diamond (10).
Minerals with a hardness greater than around 7 on the Mohs hardness scale will not leave a streak on a standard unglazed porcelain streak plate. They will instead scratch and powder the streak plate.
The color of a mineral in powdered form is called the streak color.
by simply testing the streak of the mineral. all minerals have a different streak take a streak plate and scrape the rock down it in a straight line and the color should tell you what mineral it is :) that's the best way.
Streak is the color of the finely powdered mineral when rubbed across a plate. Streak is one of the physical properties of minerals used to identify which specific mineral it is. Some minerals leave a completely different color streak than the original color of the whole mineral.