Dendritic salt is a very powdery fine grain salt which has been crystallized to provide a larger surface area. The larger surface area can help to retain fragrance. Adding approximately 5% dendritic salt to your bath salts can help them to retain their scent longer. When using to make bath salts mix your fragrance or essential oil with your dendritic salts and then blend the dendritic salts into your other salts ensuring that you mix them well.