These are Altamont "rosewood" laminates. Most laminates are made of cheaper wood, so it is unlikely they are actually rosewood, but rather dyed to look like it. The wood doesn't need to be overly strong, as the lamination provides the strength, and most lighter (in color and density), cheaper woods take dye much better than say walnut. Some of the strongest laminate I've come into contact with is made from bamboo and it is quite distinctive looking - I'd love to see a set of grips made out of it.