Goncalo Alves | The Wood Database (Hardwood) (original) (raw)

Goncalo Alves (Astronium sp.)

Common Name(s): Goncalo alves, tigerwood, jobillo, muiracatiara

Scientific Name: Astronium spp. (primarily A. fraxinifolium and A. graveolens )

Distribution: From Mexico southward to Brazil

Tree Size: 100-130 ft (30-40 m) tall,

3-5 ft (1-1.5 m) trunk diameter

Average Dried Weight: 57 lbs/ft3 (905 kg/m3)

Specific Gravity (Basic, 12% MC): 0.8, 0.91

Janka Hardness: 2,170 lbf (9,640 N)

Modulus of Rupture: 16,970 lbf/in2 (117 MPa)

Elastic Modulus: 2,401,000 lbf/in2 (16.56 GPa)

Crushing Strength: 10,770 lbf/in2 (74.2 MPa)

Shrinkage: Radial: 4.2%, Tangential: 7.8%,

Volumetric: 11.2%, T/R Ratio: 1.9

Color/Appearance: Heartwood is typically a medium reddish brown with irregularly spaced streaks of dark brown to black. Color tends to darken with age. Some pieces of goncalo alves may be completely uniform in color with no streaks or stripes.

Grain/Texture: Grain can be straight, but is usually wavy or interlocked. Fine, uniform texture with good natural luster.

Rot Resistance: Goncalo alves has excellent weathering properties, and is rated as very durable regarding decay resistance.

Workability: Goncalo alves is generally not too difficult to work, despite its high density. Figured pieces with irregular grain can pose a challenge in planing and machining operations. Goncalo alves can also have a moderate blunting effect on cutters. The wood is very resistant to moisture absorption, which can make it difficult to glue. Goncalo alves turns and finishes well.

Odor: No characteristic odor.

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

Pricing/Availability: Widely available in a variety of widths and lengths as both lumber and veneer, as well as smaller craft blanks. Prices should be comparatively moderate for an imported tropical hardwood.

Sustainability: This wood species is not listed in the CITES Appendices, and is reported by the IUCN as being a species of least concern.

Common Uses: Flooring, veneers, furniture, cabinetry, carving, turned objects, and other small wood specialty objects such as: pool cues, archery bows, knife handles, etc.

Comments: Goncalo alves is commonly referred to as tigerwood or Brazilian tigerwood among flooring dealers. The wood has superb stiffness, strength, hardness, and durability. However, density and other mechanical properties can vary widely depending on the growing site and source region. The name jobillo is sometimes used locally or among woodturners to refer to higher grades of goncalo alves.

Images: Drag the slider up/down to toggle between raw and finished wood. The first picture below shows a standard striped sample of goncalo alves, while the second shows a relatively unfigured piece (in this instance, Astronium ulei) with almost no streaks at all.

A special thanks to Steve Earis and Adam Cottrill for providing the turned photos of this wood species.

Porosity: diffuse porous

Arrangement: solitary and radial multiples, sometimes occurring predominantly as radial multiples

Vessels: medium to large, few to moderately numerous; tyloses and brownish heartwood deposits common

Parenchyma: generally not visible, though sometimes occurring on a limited basis as vasicentric parenchyma

Rays: narrow to medium, some samples may have occasional wider rays as well; normal spacing

Lookalikes/Substitutes: Curupay (Anadenanthera colubrina) can have a streaked appearance that is very similar to goncalo alves, though tyloses are common in goncalo alves’ pores—something curupay completely lacks, though there can be colored heartwood deposits present in both woods. Additionally, goncalo alves also tends to have narrower, less conspicuous rays on average, as well as less extensive parenchyma.

Notes: Another closely related species that has been formerly placed in the Astronium genus is urundeuva (Myracrodruon urundeuva). However, urundeuva tends to be about 33% heavier than goncalo alves and lacks its dramatic striping. Both goncalo alves and urundeuva produce a fluorescent response under blacklight, though urundeuva is more consistently fluorescent, while goncalo alves is more variable, only exhibiting fluorescence in roughly half the samples tested.[1]Miller, R. B., & Flynn, J. H. (2007). Fluorescent woods of the world. A Guide to the More Useful Woods of the World. Forest Products Society, Madison, 271-305.

In addition to the two most commonly traded Astronium species sold under the common name goncalo alves (A. fraxinifolium and A. graveolens), there are a few other less-common species that are also seen, such as A. lecointei and A. ulei.

Additionally, there are species commonly classified in the Myracrodruon genus (M. balansae and _M. urundeuva)_—though a recent study has suggested that these species should also be placed within the Astronium genus.[2]de Lima, E. A., Tölke, E. D., da Silva-luz, C. L., Demarco, D., & Carmello-Guerreiro, S. M. (2022). Fruit morphoanatomy of Astronium Jacq. and Myracrodruon Allemão (Anacardiaceae): taxonomic … Continue reading