Miva mahogany

• Rainforest tree grows 25–30m high.
• Stem grows to 1m diameter.
• Trunk can be heavily flanged at the base but is not prominently buttressed. Bark is brown with fine vertical fissures.
• Bark is shed in small chips.
• Freshly cut bark and sapwood have a strong onion-like odour.

• Found in rainforests from the Clarence River, New South Wales, to the Daintree River, North Queensland.

Colour

• Heartwood is red-brown.
• Sapwood is creamy pink and easily distinguished from heartwood.

Grain

• Grain is medium to coarse, often interlocked.
• Texture is uniform.
• Soft tissue (parenchyma) gives a slight figure (pattern) to the tangential surface.

• Construction: used, in the past, as sawn timber in general house framing, flooring, linings, mouldings and joinery but is rarely these days.
• Decorative: furniture, plywood, shop and office fixtures, carving, turnery, joinery.
• Others: used, in the past, for wine casks, brush stocks.

• Density: 625-640kg/m³ at 12% moisture content; about 1.5m³ of seasoned sawn timber per tonne.
• Strength groups: (S5) unseasoned, (SD6) seasoned.
• Stress grades: F5, F7, F8, F11 (unseasoned); F7, F8, F11, F14 (seasoned) when visually stress graded according to AS 2082—2000, Timber—Hardwood—Visually stress-graded for structural purposes.
• Joint groups: J3 unseasoned, JD3 seasoned.
• Shrinkage to 12% MC: 4.3% (tangential), 2.7% (radial).
• Unit shrinkage: 0.39% (tangential), 0.31% (radial)—these values apply to D. muelleri only.
• Durability above-ground: Class 3 (life expectancy 7–15 years).
• Durability in-ground: Class 3 (life expectancy 5–15 years).
• Lyctine susceptibility: untreated sapwood is susceptible to lyctid borer attack.
• Termite resistance: not resistant.
• Preservation: sapwood readily impregnates with preservatives but the heartwood can’t adequately be treated using available commercial processes.
• Seasoning: satisfactorily dries using conventional air and kiln seasoning.
• Hardness: firm (rated 4 on a 6-class scale) to indent and work with hand tools.
• Machining: machines, and turns well.
• Fixing: no difficulty using standard fittings and fastenings.
• Gluing: satisfactorily bonds using standard procedures.
• Finishing: readily accepts paint, stain and polish.

General characteristics

• Sapwood: creamy pink, distinctly lighter than heartwood.
• Heartwood: red-brown.
• Texture: medium to coarse, grain often interlocked.

Wood structure

• Vessels: medium to large, visible without a lens, mostly in short radial rows of 2–4 cells but with some solitary; lighter colour vessel contents are visible in many specimens; vessel lines prominent on longitudinal surfaces.
• Parenchyma (soft tissue): abundant in fine, wavy, apotracheal bands of slightly lighter colour than the background.
• Rays: fine, not visible without a lens.

Other features

• Burning splinter test: match-size splinter burns to charcoal—can use to distinguish from the very similar, closely related, rose mahogany, which burns to a white ash.

Figure (pattern): pleasing but subdued figure, caused by the parenchyma bands; occurs on dressed tangential surfaces.

• Boland, DJ, Brooker, MIH, Chippendale, GM, Hall, N, Hyland, BPM, Johnston, RD, Kleinig, DA and Turner, JD 2006, ‘Forest trees of Australia’, 5^th ed., CSIRO Publishing, Collingwood, Australia.
• Bootle, K 2005, Wood in Australia: Types, properties and uses, 2nd ed., McGraw-Hill, Sydney.
• Ilic, J 1991, CSIRO atlas of hardwoods, Crawford House Press, Bathurst, Australia.
• Queensland Government, DAF 2018, Construction timbers in Queensland: Properties and specifications for satisfactory performance of construction timbers in Queensland. Class 1 and Class 10 buildings, Books 1 & 2, Department of Agriculture and Fisheries, Brisbane.
• Standards Australia, 2000, AS 2082—2000: Timber—Hardwood—Visually stress-graded for structural purposes, Standards Australia International, Strathfield, NSW.