Without a doubt the most popular type of antler material is Sambar Stag. The main reason for it's popularity among knifemakers is that it tends to be very solid throughout, which makes it somewhat less susceptible to shrinking and expansion.
Sambar is somewhat of an oddity in nature.....most antler, especially those of the North American animals, tend to be a thin sheath of hard material, with a "pithy" core. As the size of the animal (and the antlers) increase, the outter sheath of harder/denser material gets thinner, and the "pithy" core gets larger..this is simple physics....if a set of 6X6 elk antlers were solid and didn't have all that "pith" in them, they would be so heavy that the animal could not carry them. This is also the case with Moose, Mule Deer, Whitetail, and Blacktail deer. Caribou antler has some unique characteristics that can make it very attractive for knife handles, but it's often hard to come by.
On the other hand, real Sambar antler will generally be solid nearly all the way through, with a single blood vessel hole, snaking along it's center axis.
In recent years Sambar has become very expensive, and rare, compared to years past. Different international regulations/bans have greatly curtailed it's importation.
Today many knifemakers who believe they are getting Sambar stag, are in fact being sold Red Stag antler, and don't realize it. The two are very similar, until you cut into them and the Red Stag antler has "pith" very much like North American species (but generally to a lesser degree). True Sambar Stag antler will rarely have any "pith" in the core, and will always have a hole, about the size of a #2 pencil lead, running at the center of the long axis.
