I was quite surprised when I found this out. Sugar isn't naturally white so sugar manufacturers have to find a way of making it white. Some sugar manufacturers process the sugar using bone char, this is what gives the sugar its white colour. You may see the bone char referred to as natural carbon. Not all sugar manufacturers use this process but just be careful when buying your sugar. An example of a company which makes sugar using bone char is the famous American 'Domino' sugar company. An example of a company which has publicly stated that it does not use bone char is the 'Imperial Sugar Company'. Silver Spoon sugar which is available in the UK only has stated that all their sugar and sweetener products are suitable for vegetarians.