I have played with heart pine for 30 yrs and you have a legitimate question as there are many terms, qualities, and sources. First, and probably most simply heart pine is the wood from the heart/center of a longleaf or loblolly pine. It is usually distinguishable by color, hardness, and smell. There are other terms that become associated with heart pine such as "virgin growth, old growth, resawn, and antique" All of these are heart pine but sourced differently. There is very little virgin grown pine in existence and those trees are very protected. There is still a fair amount of old growth around. It is usually identified by large diameter trees with very slick bark. These trees are the origin of most resawn and antique pine. Most of the warehouse beams being resawn are from old growth trees cut over 100 yrs ago. On occasion you come across a very old home with sawn virgin timbers and flooring but most of these houses have been restored/protected or torn down and resold. Many of the old Federal Style homes on the East Coast fit this category. So back to the wood. The biggest difference in quality of heart pine is resin content and tightness of grain. Since most of the old flooring, siding and milled lumber was quarter sawn tight edge grain is always the tell tale identifier of quality heart pine. Every now and then local sawyers come across large pine logs with a decent 12-18" of heart. They quarter saw and kiln dry it then call those customers that are always asking for it. Sadly the grain and color on these newer logs is nothing like what came out of the old growth stuff. It is good heart and makes a pretty floor, cabinets, and furniture but it does not have the richness of color and tight grain as is mostly desired.
