Kajal, as I recall from growing up in Trinidad, is eye liner made from filling 2 deyas (small earthen clay pots) with coconut oil, placing and lighting a wick in each then covering both with another deya. It was made traditionally on Diwalu night. In the morning when the wick was burnt out and the oil was used up, the deya was removed from the top. The black soot that coated the downturned deya is referred to as Kajal. It is used as a liner to beautify the eyes or it is also said to heal eye related issues.