Goncalo Alves

Goncalo Alves is the trade name for the wood of Astronium fraxinifolium (and the closely related A. graveolens), a medium-to-large tree of the cashew family, Anacardiaceae, native to Brazil and much of tropical South America, with its range extending into Central America and Mexico. In the flooring and lumber trade it is far better known by the marketing name Tigerwood, a reference to its bold striped figure.

The tree grows in seasonally dry and semi-deciduous forests and can reach 100 ft or more with a substantial straight bole. Freshly worked, the heartwood is a warm orange-brown to reddish-brown crossed by irregular dark chocolate-brown to near-black stripes, exactly as seen on the sample, whose bold interlocked "tiger-stripe" grain is the wood's signature. It is hard, heavy, dense, and naturally durable, which together with its striking figure makes it a favorite for both decorative and hard-wearing work.

The heartwood ranges from a reddish or orange-brown to a russet ground color, marked by irregular streaks of dark brown to blackish-brown that give the wood its tiger-stripe or zebra-like appearance; the sample's orange-brown-to-reddish-brown field with dark chocolate stripes is textbook. The pale grayish-white to tan sapwood is clearly demarcated. On exposure to light the ground color tends to deepen and the contrast between stripe and background can mellow somewhat over time.

Grain is typically straight to strongly interlocked and often wavy, producing the bold striped and sometimes roey figure prized in the wood; texture is fine to medium and uniform with a good natural luster. It is a heavy, dense wood, averaging roughly 55 lb/ft³ (about 880 kg/m³) dried, and rates around 2,160 lbf on the Janka scale — firmly in the hard range and notably harder than hard maple or white oak. Natural durability is very good: the heartwood is rated durable to very durable, with strong resistance to decay and reasonable resistance to insect attack, though the interlocked grain and density mean it can be prone to movement and checking during drying if not seasoned carefully.

Goncalo Alves's combination of striking figure, hardness, and durability suits it to work where both looks and wear matter. Its most visible use today is as prefinished and solid flooring sold as Tigerwood, and it is also popular for decking, stair treads, and other high-traffic surfaces. It appears in fine and contemporary furniture, cabinetry, and architectural veneer where the bold stripe is wanted as a feature.

It is a favorite of turners and small-project makers, showing up in bowls, boxes, knife and tool handles, pool cues, brush backs, and decorative accents. The wood's density and stability in service also lend it to specialty and durable applications such as billiard cue butts, archery bows, and sporting goods, as well as carving and inlay work where a warm striped accent is desired.

Goncalo Alves is a dense, hard wood that can be moderately difficult to work, largely because of its interlocked grain. It machines and turns to a very smooth, lustrous surface, but the interlocked and wavy grain tends to tear out on planing and jointing, so sharp tooling, light cuts, and reduced cutting angles help. It has a noticeable blunting effect on edges and cutters. It glues adequately but its density and any natural oils can interfere with adhesion and with some finishes, so surfaces may need cleaning with solvent before gluing or finishing; it takes a high natural polish and finishes beautifully. Pre-boring is advisable for nails and screws because of its hardness.

Because it can move and check during drying, quarter-sawn or carefully seasoned stock behaves best, and the wood is fairly stable once dry and in service.

Caution: as a member of the cashew/sumac family (Anacardiaceae), Goncalo Alves can cause skin and respiratory irritation, and it is reported as a sensitizer in some workers. Fine dust may provoke eye, skin, and respiratory reactions, particularly in those sensitive to related woods. Use dust collection and a respirator when sanding or machining, and good ventilation throughout.

Goncalo Alves is a moderately available imported hardwood. As Tigerwood flooring it is widely and steadily sold in North America and Europe, while solid lumber, turning blanks, and craft stock appear regularly through specialty dealers in a good range of sizes. Its price sits in the low-to-moderate tier for a figured tropical hardwood — generally more affordable than true rosewoods and accessible to hobbyists, though prime, boldly striped boards command a premium.

On sustainability, Astronium fraxinifolium is not listed on any CITES appendix and is not currently flagged as internationally threatened, so it moves in trade more freely than restricted rosewood-class timbers. As with all tropical hardwoods, responsibly sourced or FSC-certified stock is preferable given ongoing pressure on South American forests. Because "Goncalo Alves" and "Tigerwood" are both applied loosely in the trade, buyers should confirm the species when it matters.