Heartwood tends to be a medium to dark brown, sometimes with a reddish or purplish hue; some pieces may have streaks of yellowish or greenish brown. Grain is interlocked, with a medium texture and a waxy feel. Endgrain: Diffuse-porous; solitary and radial multiples; large pores in no specific arrangement, few; heartwood mineral/gum deposits present; parenchyma lozenge, aliform, confluent, and sometimes marginal; narrow rays, spacing fairly close.
Cumaru has excellent durability and weathering properties. The wood is rated as very durable regarding decay resistance, with good resistance to termites and other dry-wood borers.
Workability
Tends to be difficult to work on account of its density and interlocked grain. If the grain is not too interlocked, Cumaru can be surface-planed to a smooth finish. However, the wood contains silica and will have a moderate blunting effect on tool cutters. Due to its high oil content and density, Cumaru can present difficulties in gluing, and pre-boring is necessary when screwing or nailing the wood.
