I think there are different species, all called "purpleheart" with different characteristics.
I got a board from Yandles some years back, intending to make boxes with it, but...
- It really stinks when you cut it. The smell is, to me, nauseating. I have some offcuts left in a drawer, and they still smell horrid, years afterwards. It really puts me off using it for boxes, unless I could cedar line them or something.
- I put a pile of shavings on a sunny windowsill, and some outside in the sun. Both went a dull light brown fairly fast.
- the grain is heavily interlocked and (to me) boring to look at. It also has mineral inclusions that blunt tools fast, and a resinous sap (the smell?) that scorches very easily when crosscutting on the tablesaw.
There was a whole mini web site on purpleheart a while ago, but even that didnt have a definitive answer to the colour fading issue. I think the "intensity deepens" thing is a woody urban myth.
I have decided I hate the stuff. If God created gimmicky wood, it's either this or zebrano.
E.
PS: the splinters are proven to be Satanic in origin, probably voodoo. I got one, unfortunately: it needed exorcism, as well as a sharp scalpel and tweezers.