Black Locust (most likely) or Osage Orange — Robinia pseudoacacia

Black Locust (most likely) or Osage Orange

Robinia pseudoacacia · Hardwood

AI-generated identification · may be incorrect
Type
Hardwood
Origin
Native to Eastern North America (Appalachian region) but widely naturalized across the United States, Europe, and Asia.
Hardness
1700 lbf (Hard to Very Hard)
Durability
Very Durable. Exceptional resistance to rot and decay; it is one of the most durable woods in North America, often used for fence posts because of its ground-contact longevity.

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Grain Pattern

Straight to slightly irregular, with prominent cathedral figure on flatsawn surfaces and distinct ring-porous growth rings evident in the end grain.

Color & Appearance

Heartwood is typically yellowish-green to golden brown; sapwood is yellowish-white. It exhibits a high natural luster and tends to darken to a deeper russet brown or golden color with age and UV exposure.

Hardness (Janka)

1700 lbf (Hard to Very Hard)

Durability & Decay Resistance

Very Durable. Exceptional resistance to rot and decay; it is one of the most durable woods in North America, often used for fence posts because of its ground-contact longevity.

Value & Age

Estimated Market ValueNot an official valuation

$5.00 - $8.00 per board foot depending on grade and regional availability.

AI estimate for general guidance only — not a professional appraisal. Actual value depends on grade, dimensions, condition, and local market demand.

Wood Age Estimate
Fresh cut or recently milled, indicated by the bright, unoxidized surface and rough fuzzy fiber-tear on the edges from a coarse blade.

Common Uses

Fence posts, decking, outdoor furniture, heavy construction, mine timbers, boat building, and turning.

Geographic Origin

Native to Eastern North America (Appalachian region) but widely naturalized across the United States, Europe, and Asia.

Workability

Challenging due to its high density and hardness. It can cause significant dulling of tool edges. Glues and finishes well, though pre-boring is mandatory for screws.

Finish Recommendations

Penetrating oils or outdoor-rated polyurethanes. Its high density can make film finishes prone to peeling if not properly maintained outdoors.

Notable Features

Often fluoresces under a UV (black) light; high tannin content; very heavy and dense; excellent fuelwood due to high BTU output.

Learn more about Black Locust (most likely) or Osage Orange in the Wood Encyclopedia
Identified July 8, 2026