Shale is a type of rock, not a mineral. Streak is used to help classify minerals. It can leave a streak, but it doesn't mean anything.
A mineral with a hardness of 9, such as corundum, would not leave a streak on a streak plate because it is harder than the plate itself, which typically has a hardness of about 6. A harder mineral cannot scratch a softer material, so it wouldn't produce a streak. Streak is determined by the powder left behind when a mineral is scraped against a harder surface, and since the mineral is too hard, it cannot do so.
A ruby's streak color appears colorless because as a mineral, ruby typically does not leave a streak when rubbed against a streak plate. The color of a mineral's streak is caused by the powdered form of the mineral, revealing its true color when scratched against a ceramic plate, but in the case of ruby, its hardness and structure prevent it from leaving a visible streak.
The mineral Quartz leaves a colorless streak.
The colour of the streak left by a mineral is one of the features used to identify it. For instance, haematite leaves a red streak, malachite leaves a light green streak, while quartz, calcite and gypsum all leave a white streak.
The mineral graphite is soft enough to leave a mark on paper. We use graphite, which is a form of carbon, as pencil lead. And it works pretty darn well at leaving marks on paper.
Graphite is a mineral that does not leave a clear streak.
The lack of a streak would indicate that the mineral is harder than the streak plate, or the color of the streak is the same as the color of the streak plate.
The streak of Jade is white.
A mineral with a hardness of 9, such as corundum, would not leave a streak on a streak plate because it is harder than the plate itself, which typically has a hardness of about 6. A harder mineral cannot scratch a softer material, so it wouldn't produce a streak. Streak is determined by the powder left behind when a mineral is scraped against a harder surface, and since the mineral is too hard, it cannot do so.
Mineral streak is the color of the powder produced when a mineral is scratched on a porcelain streak plate. It is a useful property for identifying minerals, as different minerals can leave distinctively colored streaks.
Diamond will not leave a streak on a porcelain streak plate because diamond is harder than the streak plate. It will leave a scratch on the streak plate for the same reason.
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.
It leaves a scratch instead of a streak because Topaz has a higher number on the Moh's scale compared to the streak plate.
Hematite is typically a dark gray to black mineral with a reddish streak, while galena is a silvery-gray mineral with a cubic crystal structure. One way to differentiate between them is by performing a streak test: hematite will leave a reddish-brown streak, while galena will leave a gray streak. Additionally, galena is heavier than hematite and has a metallic luster.
A ruby's streak color appears colorless because as a mineral, ruby typically does not leave a streak when rubbed against a streak plate. The color of a mineral's streak is caused by the powdered form of the mineral, revealing its true color when scratched against a ceramic plate, but in the case of ruby, its hardness and structure prevent it from leaving a visible 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.
A streak test is used to determine a minerals streak color. This can help in with the identification of minerals. A streak test is performed by rubbing the mineral on an unglazed ceraminc tile, then observing the color of the streak which is left behind. All minerals do not leave streaks. Harder minerals will not streak, but this can also be used as a tool for identifying the mineral, if you are familiar with the hardness scale.