Oil of guaiac is a fragrance used in soap. It comes from the Palo Santo tree. Oil of guaiac is produced through steam distillation of a mixture of wood and sawdust from Palo Santo. It is sometimes incorrectly called guaiac wood concrete. It is a yellow to greenish yellow semi-solid mass which melts around 40-50 ºC. Once melted, it can be cooled back to room temperature yet remain liquid for a long time. Oil of guaiac has a soft rose like odor, similar to the odor of Hybrid Tea roses or violets. Because of this similarity, it has ...