African Blackwood

African Blackwood (Dalbergia melanoxylon)

Common Name(s): African Blackwood, Mpingo (Swahili)

Scientific Name: Dalbergia melanoxylon

Distribution: Dry savanna regions of central and southern Africa

Tree Size: 20-30 ft (6-9 m) tall, 2-3 ft (.6-1.0 m) trunk diameter

Average Dried Weight: 82 lbs/ft³ (1,310 kg/m³)

Basic Specific Gravity: 1.08

Hardness: 4,730 lb_f (21,060 N)*

*Estimated hardness based on specific gravity (see comments below).

Rupture Strength: 31,000 lb_f/in² (213,790 kPa)

Elastic Strength: 2,980,000 lb_f/in² (20,550 MPa)

Crushing Strength: 10,470 lb_f/in² (72.2 MPa)

Shrinkage: Radial: 2.5%, Tangential: 4.5%, Volumetric: 7.6%, T/R Ratio: 1.8

Color/Appearance: Often completely black, with little or no discernible grain. Occasionally slightly lighter, with a dark brown or purplish hue. The pale yellow sapwood is usually very thin, and is clearly demarcated from the darker heartwood.

Grain/Pore: African Blackwood has a fine, even texture, with small pores that should not require filling; the grain is typically straight.

Endgrain: Diffuse-porous; both small and medium sized pores in no specific arrangement; solitary and radial multiples of 2-3; dark brown deposits present; growth rings may be distinct due to marginal parenchyma; rays not visible without lens; parenchyma banded (marginal), apotracheal parenchyma diffuse-in-aggregates, paratracheal parenchyma can also be vasicentric, and aliform (winged).

Durability: Heartwood is rated as very durable in regards to decay resistance, though only moderately resistant to insect attack. The sapwood is commonly attacked by powder-post beetles and other borers.

Workability: Very difficult to work with hand or machine tools, with an extreme blunting effect on cutters. African Blackwood is most often used in turnery, where it is considered to be among the very finest of all turning woods—capable of holding intricate details, and is reported to hold screw threads nearly as well as metal.

Scent: African Blackwood has a mild—though distinctive—scent while being worked.

Safety: Although severe reactions are quite uncommon, African Blackwood has been reported as a sensitizer. Usually most common reactions simply include eye, skin, and respiratory irritation. See the articles Wood Allergies and Toxicity and Wood Dust Safety for more information.

Price/Availability: African Blackwood is very expensive, on par with true ebonies such as Gaboon Ebony in the Diospyros genus. Since the tree grows so slowly, and is generally small and gnarly, available boards tend to be narrow—though large clear sections are occasionally harvested from older trees that yield bookmatched guitar backs (~8″ wide).

Comments: To be considered the original ebony, African Blackwood was imported and used in Ancient Egypt thousands of years ago. Even the name “ebony” has an Egyptian derivation as “hbny”—which has been shown to refer to primarily to Dalbergia melanoxylon, rather than the species which are considered to be ebony today: such as those in the Diospyros genus. In addition, African Blackwood is technically in the Rosewood genus (Dalbergia), and is more stable and resistant to movement and warping than other types of ebony.

African Blackwood is considered to be among the hardest and densest of woods in the world; indeed, among some 285 species tested, (including Lignum Vitae), Gabriel Janka originally found African Blackwood to be the very hardest. Unfortunately, many online sources list African Blackwood’s Janka hardness at only ~1700lb_f—which seems very unlikely given its confirmed specific gravity.

Some common uses for African Blackwood include: musical instruments (guitars, clarinets, oboes, etc.), inlay, carving, tool handles, and other turned objects.

Related Species:

Brazilian Rosewood (Dalbergia nigra)

Burmese Rosewood (Dalbergia oliveri)

Cocobolo (Dalbergia retusa)

East Indian Rosewood (Dalbergia latifolia)

Honduran Rosewood (Dalbergia stevensonii)

Kingwood (Dalbergia cearensis)

Madagascar Rosewood (Dalbergia baronii)

Sissoo (Dalbergia sissoo)

Tulipwood (Dalbergia decipularis)