Admin Why does a diamond not leave a streak on a streak plate?
The reason for this is because the streak plate (porcelain tile) only has a hardness (Mohs scale) of 7, which means anything with a hardness greater than 7 will “scratch” the streak plate rather than leave a “streak”.
What mineral does not leave a streak?
Streak is a more reliable property than color because streak does not vary. Minerals that are the same color may have a different colored streak. Many minerals, such as the quartz in the Figure above, do not have streak.
Which of the minerals in your classroom collection does not leave a white streak on darker unglazed porcelain?
Color, Streak, and Luster. Diamonds are popular gemstones because the way they reflect light makes them very sparkly. Turquoise is prized for its striking greenish-blue color. Notice that specific terms are being used to describe the appearance of minerals.
Why does the streak test work only on minerals?
The Streak Test: Marks, known as “streaks,” are produced by scraping mineral specimens across unglazed porcelain plates. Many minerals produce a white streak, and some geologists prefer using a black streak plate for these minerals because the mineral particles in the streak are easier to observe.
What mineral in your classroom collection is harder than a streak Plate & leaves no streak is opaque to translucent white or gray and has a vitreous luster?
One is pyrite. What is the other mineral that fits this description? What mineral is harder than a streak plate & leaves no streak, is opaque to translucent white or gray and has a vitreous luster? Diamond is literally the hardest known mineral on Earth, without exception.
How can an unglazed ceramic plate be used to identify a mineral?
The streak test is done by scraping a specimen of the mineral across a piece of unglazed porcelain known as a “streak plate.” This can produce a small amount of powdered mineral on the surface of the plate. The powder color of that mineral known as its “streak.”