THe wife and I were out last weekend ,12ish miles NNW of Rich HIll,AZ and found a purty rock about 4 "x7" and couple inches thick. Found others of interest but not as purty.. BRought back 200 pounds or so of 'em. Lots of large feldspar phenocrysts or porphyroblasts . to throw out some bit words I found on WIKI.
- one side of it is faced with quartz crystal that looks like it was hit with some secondary hydrothermal erosion/depostion that's amber/brownish. Sortof melted the crystals down a bit so the terminations are few .
Below the crystals (moving outward from the pocket) colors range the gamut with some purply redish black eye candy.
VInegar didn't do squat,next thing I had around to try was "metal prep"( phosphoric acid.)
It's been in that for a day and not a bubble from the surface/ hint of reaction or change surface coloration or shape..
CLR is next and I guess I have to charge up my camera battery and learn how to download a pic or two
Mike's seen a purty rock or two out there,,,..