Heart pine is southern yellow pine. It's just marketing slang to increase the price. Salvaged or reclaimed usually has tighter growth rings due to different growing conditions hundreds of years ago. Heart wood is the center of a tree that is no longer living and usually darker than the sap wood. Loblolly, shortleaf pine, slash and some others were used and are what are now advertised as heart pine by reclaimed and salvaged dealers. Unscrupulous dealers will even sell newly harvested syp as salvaged or reclaimed. therefore heart pine. True salvaged/reclaimed will tend to be harder due to the hardening of the pitch in it over time, but it is still yellow pine.
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