Can someone tell me what is Dark Timber which is used by some guys as handle material?

I spent 40 years as forester and woodworker and never heard of such a thing, except in the vague sense that some woods like walnut, Ebony, etc are darker than other woods like Maple or Hickory.  It's probably a made up term being used as some sort of magical marketing hype.

I always thought of dark timber as the north side of a mountain with timber on it. Elk like to hang out in dark timber, especially if it is hot.

It seems o be a synthetic material. If you google bowbuilders and dark timber there is some guys using it instead of fenolic in the bow handle. they are not sponsors here so I could not list their names. Coul;d not find a source listing it though.

Are you asking about "Dark Matter"?

pparently also heavier, giving some weight to handles/bows.

Always assumed that the "dark matter" was black paper phenolic. But what do I know. Never seen the stuff.

Only dark timber or dark matter I'm familiar with is that BLACK Ipe.