Question, did you find it in the same area you've been digging in? If so a follow up question for EU, does amphibole occur in pegmatite zones? I'll wiki it later.
Amphibole~ Hornblend series.... had not thought that, actually had to look it up, and what EU is saying about the cleavages. Hrm. Thanks for that hot potatoe. Hehh I may be hung up on tourmaline... been picking at a small part of my collection to much recently.
Unsure how to go about further classification. In another part of my collection I have similar stuff that I attributed to horn blend.... stuff from Colorado taken from volcanic dikes and granatiod areas.
DD, the difference between hornblende, Pyroxene and Amphiboles can be tricky.
The difference is the angle they cleave at, I want to recall. Amphiboles form a more V shaped cleavage.
Refer to a gabbro for pyroxenes and compare.
Pyroxenes rarely occur in felsic rocks, amphiboles usually in metamorphic rock and hornblende in felsic rock. That's just from memory, could be good idea to look it up.