After a long time working out the kinks, Tungsten Carbide is now and option for wood inlay type rings.   Tungsten Carbide for an exterior liner will simply not be possible.  The material is so hard that at the required thicknesses, it would shatter.  

Tungsten Carbide and Old Rip Van Winkle barrel oak:

Tungsten Carbide and Exhibition Grade Hawaiian Koa:

Not all Tungsten Carbide rings are the same! Tungsten and Carbon are elements that would naturally be a powder. They are combined at very high temperatures with binders to make an incredibly dense, nearly indestructible metal. The choice and quality of these extra elements are what sets this top quality, American made ring apart from its mass-produced-in-China counterparts. While it is possible to shatter a WedgeWoodTungsten Ring, it is not easy. 

Because Tungsten Carbide exhibits unparalleled scratch resistance, it is the most durable possible choice for a wood ring. Unless you routinely encounter industrial diamond abrasives, your ring will never scratch. It is 10x harder than gold and 5x harder than steel. It will also not bend or deform in any way. It has a significant heft, nearly the weight of solid pure gold.

The finish is permanent and will never corrode. The color is a rugged, dark gray. 

Comfort fit.  6mm or 8mm available.

Looking for a solid Tungsten Carbide ring without wood?  Your request bores me!  However, that is readily available at my other shop, Firefly Rings:

http://www.fireflyrings.com/tungstencarbiderings/