The three most common of these salts are olein, found in olive oil, palmitin, in palm oil and human fat, and stearin, in lard.
"An Introduction to Chemical Science"
R.P. Williams
Stearin and palmitin are hard fats, crystalline in structure, and with a high melting point, while olein is a liquid.
"Human Foods and Their Nutritive Value"
Harry Snyder
Lard is composed of the three fats, olein, stearin, and palmatin, and has a number of characteristic physical properties, as specific gravity, melting point, iodine absorption number, as well as behavior with various reagents, and these enable the mixing of other fats with lard to be readily detected.
"Human Foods and Their Nutritive Value"
Harry Snyder