Heartwood tends to be a golden or medium brown, with color darkening with age. Grain is straight, though it can occasionally be wavy or interlocked. Coarse, uneven texture and moderate to low natural luster. Raw, unfinished wood surfaces have a slightly oily or greasy feel due to natural oils. Easy to work in nearly all regards, with the only caveat being that Teak contains a high level of silica (up to 1.4%) which has a pronounced blunting effect on cutting edges. Despite its natural oils, Teak usually glues and finishes well, though in some instances it may be necessary to wipe the surface of the wood with a solvent prior to gluing/finishing to reduce the natural oils on the surface of the wood.