"Hormigo" is a Latin American wood name, and if you've spent much time there, you'll know those names mean one thing in one country and another somewhere else. Scientific names are the only sure way to know what wood someone's actually referring to.
That said, we've either used Hormigo a lot, or we've used a wood of the same genus. We called it Cristobal, most call it Granadillo and a few others say Hormigo. Every wood we've tried from that family has very similar characteristics. What we used often had straight fine grain with slight swirl, sometimes with striping, and varied from a dark amber to more of a shimmering gold. Very pretty wood and finishes very nicely.
The sound is great as well. It is often described as similar to many rosewoods, but with a more clearly defined, ringing tone in the higher registers and not quite as much bass. Eddie's site reference mentions Marimba keys, and that is what our woods were used for, along with Guitar bodies. A Marimba key, of course, has to resonate well and this wood is excellent in that regard. Any sort of soundboard can work - different flavor of course, but we've liked the results with European Spruce (brighter) and Yellow Cedar (smoother) in particular.
The attached picture shows a bit more uncommon grain pattern. As mentioned, straight fine grain with a bit of swirl or striping is most common, but this sort of figure can be had as well. Photo is of one of our Classical Tenor Guitars in the spray room.
Our particular species is now in CITIES Appendix II, and we don't use it any more (the little guys don't get the permits). Wood bought from a U.S. or E.U. vendor will have been harvested legally.