No wood floor is completely scratch resistant, but some handle pet claws and furniture scrapes better than others. It's not just differences between wood species that matter, but also the finish material. In general, the hardest flooring comes from the tropics as is prefinished at the factory with a baked-on polyurethane or aluminum-oxide finish. The least durable flooring materials are softwoods, and any flooring material is more scratch prone when finished on site with shellac, oil or less than three coats of polyurethane.
The hardest and most scratch-resistant species, such as ipe, cumaru and jatoba, come from the tropics, and they typically score 3,000 pounds or more. Domestic hardwoods and raw bamboo, on the other hand, are about half as hard. Softwoods, such as pine, fir and carbonized bamboo, rarely score more than 1,000 pounds, making them particularly vulnerable to scratching.
Even a softwood floor can resist scratches to some degree if the wood has a tough, durable finish. The hardest finishes, which come on top-grade prefinished flooring, must be applied by the manufacturer. Finishes applied on site after installing unfinished flooring or refinishing an existing floor aren't as durable, although oil-based ones are more scratch resistant than water-based ones. If you're going to apply a finish yourself, choose an acid- or moisture-cured product that contains nano-particles of aluminum oxide for maximum durability. There isn't any difference in durability between a satin and gloss finish, but a gloss finish will show scratches more easily.