white board marker 3pcs+mini board eraser 18.7*15.5*2cm 18.7*15.5*2cm
Specially designed magnetic eraser allows easy adhesion to magnetic drywipe boards.
Lightweight Magnetic Eraser.Soft Absorbent surface makes board cleaning easy.
Bi-office.Visit our shop for all different drywipe markers, boards and accessories!
Many more difficult-to-find stationery items available in our shop,
Feel free to message us should you have any questions.
Chalk is a soft, white, porous sedimentary rock, a form of limestone composed of the mineral calcite.
Calcite is calcium carbonate or CaCO3. It forms under relatively deep marine conditions
from the gradual accumulation of minute calcite plates (coccoliths) shed from micro-organisms called coccolithophores. It is common to find chert or flint nodules embedded in chalk.
Chalk can also refer to other compounds including magnesium silicate and calcium sulfate.
Chalk is resistant to weathering and slumping compared to the clays with which it is usually
associated, thus forming tall steep cliffs where chalk ridges meet the sea. Chalk hills,
known as chalk downland, usually form where bands of chalk reach the surface at an angle,
so forming a scarp slope. Because chalk is porous it can hold a large volume of ground water,
providing a natural reservoir that releases water slowly through dry seasons.