You are buying a completely natural untouched pieces of lump chalk. They have come direct from the ground as natural as it can come. 
Please note picture is of more than 1kg. 
This is something we offer to our tortoise from hatchling to large full grown adult. 
Calcium is so important in a reptiles diet. It helps with bone and shell growth.  
It is also used for females when producing eggs.  
 
Directions - You can simply leave in the enclosure, break up and leave dotted around the enclosure. You can also rub together to create a calcium dust and sprinkle on food 
                   Tortoise will also keep been trimmed with this through the process biting the lump chalk.
 
Larger amounts available!