It is entirely possible Altamont works with hardwood as well as Dymondwood.
My experience is limited to their current offering of S&W J frame grips, which are clearly Dymondwood based on the pattern of the wood:
http://www.altamontco.com/experimental/products/pistol/smith_and_wesson/#Smith_and_Wesson_jframe.php
You can see each individual piece of colored plywood stacked laterally near the grip frame. Altamont themselves referred me to their source for Dymondwood when I called to ask about the material of the grip I received. They referred me to Rutland Plywood corporation, whom provided me with a material safety data sheet on the material. I was specifically concerned about the quantity of formaldehyde and phenol/epoxy resins that offgas naturally from the wood and increase when the wood is machined.
http://www.rutply.com/
Yours, however, may be in fact rosewood in which case you got a better deal than I did. However, the pictures you posted of model 10 super rosewood grips appear to be Dymondwood. Although there is nothing wrong with Dymondwood, I was under the impression of buying hardwood, as were you. The same thing happened to me when I received a pair of Badger grips in "Walnut" which were actually "Walnut flavored Dymondwood". I still like and use the grips. In some cases Rutland will compress hardwood plywood and then morph it into Dymondwood, further blurring the distinction between materials.
Altamont, at the very least, is generally more transparent in their use by labeling the wood "Super Rosewood" and "Super Walnut". In almost all cases Dymondwood will have near symmetrical lines on the front and rear surface of the grip frame where the plywood has been stacked and compressed.
That said I think the original posters grips will serve their intended purposes and be a fine upgrade to the OEM stocks... this is more of an academic point about many grip manufacturers today. Unless you had developed an allergic reaction to formaldehyde, in which case you would want to limit your exposure to Dymondwood. Cocobolo and other hardwoods often provoke an allergenic reaction in some folks as well.
Each line is one piece of super-compressed plywood, such that one Dymondwood grip may have as many as 30 - 50 pieces of compressed plywood visible.
The same markings are apparent on the "Walnut" versions posted by the OP as an example of the ones ordered, the ones posted by Skidder, and the super rosewood on your model 10. They do look nice, and probably used to be walnut, or rosewood, or birch, or some type of wood
Rutland could probably tell you.
These types of material are often referred to as engineered wood laminates. It is used quite widely and not only in firearms but in knife handles, furniture, chess pieces, art, and other industry.