Top portion is finished with water-base urethane; bottom with oil-modified polyurethane.

Color: Heartwood is yellowish to orange-brown when freshly cut, turning brown or dark red-brown upon exposure.
Grain: Straight to interlocked or wavy; coarse texture.
Variations within species and grades: Moderate to high variation in color.

Hardness (Janka): 1925; 49% harder than Northern red oak.
Dimensional Stability: Excellent (change coefficient .00158; 57% more stable than red oak). However, actual installations have demonstrated significant movement in use.
Durability: Strength is comparable to hickory, but density is somewhat lower.

Sawing/Machining: Sawing is difficult; wood gums saw teeth and dulls cutting edges; carbide tooling recommended.
Sanding: Sands satisfactorily.
Nailing: Good holding ability.
Finishing: Wood stains black in contact with ferrous metals or moisture.
Comments: High resistance to termites.

Information is from The National Wood Flooring Association
"Wood Species Used in Wood Flooring"