Santalum album from Mysore is considered to be the finest sandalwood available, but it has become endangered and alternatives are often used. Recently some renewable plantations have begun to offer true Indian sandalwood. I've been able to purchase some very nice Santalum album again and hope these sources will be sustainable. Natural alternatives include plantation grown sandalwood from Tamil Nadu, Australian sandalwood (Santalum spicatum), and Vanuatu or New Caladonian sandalwood (Santalum austrocaledonicum). I have some New Caledonia sandalwood absolute that I like very much. Fine synthetic substitutes are frequently added to the plantation grown woods to create sandalwood accords.