This box of 12 Mercurius blackboard chalks are chosen by many Waldorf schools due to their vibrant and intense colour application.
They are NOT dustless chalks, and therefore they lack the ingredient used to harden the type of chalk that is best for our children to use on concrete etc. Because of the lack of that ingredient these are very much like a chalk pastel, and will give great results on blackboards.
As with all our products, we have tested and approve of these beautiful chalks.
Here's the official information on the Mercurius website:
Mercurius Blackboard Chalk comes in soft pastel colours to make creating beautiful blackboard drawings easy. It has great coverage and blends easily. The square pieces are covered with paper to help keep fingers clean.
The colours follow the Stockmar colour range. Cardboard box, 12 crayons, 88x12x12 mm (3.46x0.47x0.47 inch), 12 colours assorted. Colour: 01 carmine red | 02 vermilion | 03 orange | 04 golden yellow | 05 lemon yellow | 06 pale green | 07 dark green | 10 dark blue | 12 red violet | 13 red brown | 19 cobalt blue | 24 pale flesh"