Here is a list and some explanation of the different blank materials that I use when crafting my pens.
Wood
One of our most common materials, wood is used in everything imaginable. Some examples of woods that I like making pens from are:
Bethlehem Olive Wood Spalted Maple
Kingwood Leopardwood
Mesquite Aambonya Burl
Acrylic
Acrylic is, in the most common sense, plastic. However, it isn't the same plastic as your computer keyboard is made of or the cup that your soft drink came in. Acrylic suitable for making pens must be strong, stable, and machine-able. Additionally, it must be dense enough to be polished to a mirror finish.
Blends
Blends are pen blanks that have a combination of materials, i. e. wood and acrylic. Pens made from blends are truly one-of-a-kind creations.
TruStone
Trustone is, "produced from approximately 85% natural stone ore. The ore is pigmented, compressed into blocks and impregnated with approximately 15% acrylic gem resin for structural integrity." http://www.rtresearch.net/
Vintage Materials
In order for me to consider a blank to be vintage, it must be made of something which is either no longer being made, or is of such rarity that it might as well no longer be made. One of my favorite vintage materials to use is serpentine Cebloplast, from Mazzucchelli of Italy. My understanding is that this material was made between 1929 and 1933 for the Shaeffer pen company. Sadly, this material is in short supply, and like the once common dodo is destined for extinction.