PVR states:

Patrick Olguin schreef
Even these might not help all that much, seeing
as you're using purpleheart. This wood is not only hard, it's full of
silica [...]

+ + +
Nope. It isn't. Not resistant to teredo either

According to William Lincoln, it exudes a gummy residue if heated by dull
tools. Might be messy. I've always made sure tools for purpleheart are
especially sharp. While teredo (shipworm) is not a particular problem outside
oceans (docks, ships, boats, similar structures), powder post beetle can chew
up the sapwood.

Charlie Self
"The function of posterity is to look after itself." Dylan Thomas