Black Locust (most likely) or Osage Orange

Robinia pseudoacaciaHardwood

Black Locust (most likely) or Osage Orange

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 Description

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 Rating

1700 lbf (Hard to Very Hard)

Durability Rating

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.

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.

Market Value & Sustainability

Estimated Market Value

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

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.

Sustainability Status

Highly sustainable. Not listed by CITES or the IUCN; considered invasive in some regions due to fast growth and vigor.

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.

Notable Features

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

Finish Recommendations

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

Identification Confidence

Medium-High. The distinct ring-porous structure, pale greenish-yellow hue, and the rough, 'stringy' nature of the cut fibers are characteristic of Black Locust.

Identified on 7/8/2026