The chalk comes from limestone. Limestone was formed from the accumulated deposits of tiny marine animals over 70 million years ago.

Art.Nr.  Amount  Description    Picture 
205-111200
205-111210  
1 kg
15 kg  
Stone Chalk, fine   One refers to the pulverized tender limestone
as stone chalk which originates from alpine
rock forms.  
205-111300
205-111310  
1 kg
25 kg  
Champagne Chalk   This chalk comes from the Champagne region of
France, specifically in the area around Reims.  
205-111400
205-111410 
1 kg
25 kg  
Bologna Chalk   The chalk denotation is not correct for this material. It is
actually calcium sulfate or more commonly - plaster. 
205-111500
205-111510 
1 kg
25 kg  
China Clay, fine   China chalk is not a genuine chalk but actually Aluminium
silicate or a product of the weathering of feldspar.