Organic oils, such as shay butter (also palm oil, coconut oil, etc.), are best used on organic materials. For instance, amber, ivory, bone, horn, and wood. For amber, I recommend canola oil (because it has the same specific gravity as amber, and is what was traditionally used in the German and Polish amber trade 100 years ago). For wood, I recommend walnut oil. It dries very hard, and brings out grain wonderfully well.

For applications onto minerals or artificial products, the oil should be mineral oil. See my reply to Thomas, above. If one were going to apply animal oil to a mineral, I recommend nose grease. (No kidding.) Rubbing a discolored lapis bead along the length of your nose (and particularly at the juncture of the wings of the nose) will make it immediately look much better, and it persists well.

Jamey