Cocobolo is an attractive, colorful wood with an interesting grain. Due to its lower density it offers a smooth, mellow sound with plenty of warmth.  

Cocobolo is an extremely dense (it doesn't float!) hardwood from South America. The wood has a natural, oily finish. It requires no finish coat of varnish, shellac or any kind of sealer.
Cocobolo does not soak up water readily, and therefore does not swell when wet. Nor does it change size appreciably due to variations in temperature. It's easy to see why the physical properties of Cocobolo make it ideal for duck and goose call stoppers. Often a call can have a barrel made from other woods; the stopper is usually Cocobolo on a fine call. Other woods, such as rosewood, cherry and diamond wood, to name a few, work well as call stoppers - as do modern synthetics.
Call barrels can be made from anything, plastic or wood - walnut, bois d' arc, even cedar. It's the stopper that determines the sound of the call.

Cocobolo is in the Leguminosae Family and grows mostly in the Pacific regions of Central America extending from Panama to southwestern Mexico. Of limited occurrence, usually in the drier uplands. Somewhat variable in color, deep rich orange-red with black striping or mottling on exposure to air. Fine grain, straight to interlocked; oily; Basic specific gravity >0.98. Cocobolo is denser and stronger than Brazilian Rosewood. It has excellent drying properties, free of surface and end checking. Shrinkage is usually low; high stability in use. Very low moisture absorption. Cocobolo has excellent machining characteristics; natural oils give the wood a good polish.
We use Cocobolo for all of our fretless basses because of the extreme durability and long life of this wood. Its natural hardness and oiliness keep it from developing the grooves common to other fingerboard woods. 

We get it from Mexico and have sold it mostly for Laminate Body Tops.

Orange Cocobolo is a beautifully colored hardwood, much like ebony, but with a lot of orange, gold, and tones of brown in it.

From Central America: Mexico, Nicaragua, and Panama.
Color varies from orange to deep red with irregular patterns of purple or black. Grain is usually straight and fine textured. Contains a high oil content, which acts as a barrier to water absorption and imparts a waxy appearance when rubbed.
Common uses include cabinets, chessmen, inlay work, furniture, cutlery handles, and ornamental work.
Specific Gravity is 1 (very dense). Turns readily to yield smooth surfaces.

Streaks of dark maroon, black, purple and red brown.

There are roughly a dozen species of true rose woods in the world. (Yes, they smell like roses when cut with a saw.) A partial list would include Tulip wood, King wood, Cocobolo, East Indian Rose wood, and Brazilian Rose wood. With the exception of the latter, these are oily to the point of being dead in the tone department. So what is the point in coveting these materials when there are sonic superiors available? The problem is that in the public mind, rose wood is cool, so it has long been over harvested. Because of this Brazilian Rose wood has been banned from importation to the United States for over twenty five years. 

I think Brazilian Rosewood is over rated and overpriced and I would classify it as just another scamwood. Cocobolo doesn't cost as much and in many cases is cosmetically prettier

Ed Roman