Black Locust (with probable spalting/staining)
Robinia pseudoacacia • Hardwood
Grain Pattern
Straight to slightly wavy with a flat-sawn cathedral pattern visible in the center. Features irregular dark streaks indicative of early-stage spalting or mineral staining.
Color Description
Pale greenish-yellow to golden brown heartwood with light yellow-white sapwood. High natural luster and chatoyance; tends to darken to a deeper russet brown upon exposure to UV light.
Hardness Rating
1,700 lbf (Hard to Very Hard)
Durability Rating
Very Durable; exceptionally resistant to rot, decay, and insects. Frequently used for ground-contact applications without chemical treatment.
Common Uses
Fence posts, decking, outdoor furniture, boat building, tool handles, mine timbers, and firewood.
Geographic Origin
Native to the Appalachian Mountains and Ozark Plateau of the United States; widely naturalized throughout North America, Europe, and Asia.
Market Value & Sustainability
Estimated Market Value
$6.00 to $10.00 per board foot depending on width and degree of figure/defect.
Wood Age Estimate
Freshly milled to slightly seasoned. The bright greenish-yellow hue suggests it has not yet undergone significant UV-induced darkening (oxidation).
Sustainability Status
Not listed in CITES Appendices or on the IUCN Red List; considered highly sustainable and even invasive in some regions outside its native range.
Workability
Difficult to work due to high density and hardness. Blunts cutting edges quickly; frequent sharpening required. Glues and finishes well, though its high density can make nailing difficult without pre-drilling.
Notable Features
Glows/fluoresces under UV (black) light; exceptionally high rot resistance; high BTU value when burned; contains some toxins that can cause irritation in sensitive individuals.
Finish Recommendations
Penetrating oils or spar varnishes are recommended for outdoor use. For indoor use, a clear polyurethane or wax preserves the natural luster and fluorescent properties.
Identification Confidence
High; the distinct greenish-yellow tint, tight grain structure, and characteristic dark mineral streaking are classic markers for Robinia pseudoacacia.