We all know and love Jamaican Black Castor Oil (JBCO), but did you know there's a another form of castor oil? Yes, welcome Haitian Black Castor Oil (HBCO)! While both are from beans that have been roasted and heat extracted, Jamaican Black Castor Oil usually has more ash from burning than Haitian Black Castor Oil does. HBCO also has more Ricinoleic acid (an unsaturated omega-9 fatty acid) and Iodine (which can kill fungus and bacteria). Now JBOC does tend to be more alkaline than HBCO, but an article from Sunny Life Up suggests "the lower PH means this thick oil can coat the hair better [and makes] an awesome option for sealing in moisture and smoothing split ends!"
Here's some other great research:
"Independent laboratory tests of one batch of castor oil from two leading brands showed that JBCO has .014% lower water content than HBCO and 10.27 higher saponification value, suggesting that JBCO is suited to soap-making. HBCO on the other hand, has 2.04% more ricinoleic acid and 3.27 more centigramsof Iodine per gram (an indicator of fatty acid saturation) suggesting it is ideal for hair and skin."
I didn't mention clear castor oil because "[it] goes through a bleaching process that removes its natural color and strips most of all the healing properties and vitamins that are needed for hair growth, skin care, and anti-bacterial/anti-inflammatory properties." - blackcastoroil.info