This is what I've read about Lignum Vitae (Ironwood).Its available from West Indes,Central America,and,Northern South America.
there's a specie's that grows in Veezuela that has similiar propertie's called Maracaibo Lignum Vitae.It's some time used as a substitute.
This didn't answer your question,but maybe someone can.I tend to believe it's the real stuff.
I have a large ,and small dual thumb stud's Lignum V Sebenza's.