I think calcium carbonate is used in very small doses as an antacid but can be lethal in larger quantities. It is also the main component of pearls @Phoenix_Rising @Faith-and-Hope

@Phoenix_Rising This has been the most wonderful day and I am so, so, so pleased that you have enjoyed it - you really deserved it to be a special day for you. 

Happy, happy birthday little turtle (better start planning for next year's now lol)

The forum would not be the same without you - you are an amazingly humorous, intelligent and caring little 'human in a shell' and it really is a pleasure to know you