Longitudinal section of Sequoia burl (Sequoia sempervirens), synonyme : Redwood burl, Californie, USA Wood sample, sanded and without any further surface treatment: 8 x 12 cm; wood origin: California, USA; average wood density: 415 kg/ml at 12% moisture; Janka hardness test: 204 kgf, 450 lbf, 2000 N; Monnin hardness test: 1.3 to 2.5; IUCN Red List = EN (2011)