topaz
topaz
hardness
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.
Streak is a method used to help identify minerals. A mineral can have very similar characteristics such as luster, colour, hardness, specific gravity ect, but even minerals with very similar characteristics including colour can have different streaks...which is the 'colour' the mineral makes on a scratch plate when drawn accross it in a stroke..thus creating the streak.
what is the color of the powder called that a mineral leaves when scratched across a special plate
A minerals hardness is its relative ability to scratch or be scratched by other minerals. Diamond, for instance, can scratch all other minerals because of its hardness. Streak is the color of the mineral when powdered. This is usually accomplished by the streak test (swiping the mineral across an unglazed porcelain surface) which reveals a mineral's streak color, which may differ from the color of the specimen being tested.
A streak plate is used to determine the streak colour of a mineral. You take the mineral and scratch it against the streak plate, and it will create a coloured streak on the plate. The streak is not always the same colour as the mineral itself.
hardness
It leaves a scratch instead of a streak because Topaz has a higher number on the Moh's scale compared to the streak plate.
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.
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.
The streak of a mineral can distinguish between two samples that have the same color. The streak is often a different color. To test streak, use a streak plate. This is a piece of unglazed porcelain, like the back side of a tile.
a streak test is a test wheree you rub a mineral across a streak plate to see the color of its streak, which is a better indentifying factor of the mineral than the external color. A scratch test is when you scratch a mineral to find out its hardness on the Mohs Scale of Hardness. This is also another useful identifying factor
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.
Streak is a method used to help identify minerals. A mineral can have very similar characteristics such as luster, colour, hardness, specific gravity ect, but even minerals with very similar characteristics including colour can have different streaks...which is the 'colour' the mineral makes on a scratch plate when drawn accross it in a stroke..thus creating the streak.
what is the color of the powder called that a mineral leaves when scratched across a special plate
A minerals hardness is its relative ability to scratch or be scratched by other minerals. Diamond, for instance, can scratch all other minerals because of its hardness. Streak is the color of the mineral when powdered. This is usually accomplished by the streak test (swiping the mineral across an unglazed porcelain surface) which reveals a mineral's streak color, which may differ from the color of the specimen being tested.
I do not have a picture, but when you scratch aquamarine on a streak plate, the powder will be white colored.