I see that it has been months since I wrote anything here. I wondered why I had no energy. Then one day I was in terrible pain, and ended up having a lithotripsy. They broke up a 10 mm. kidney stone with sonar waves. I told the surgeon I was an amateur mineralogist and he assured me that stones forming in the urinary tract aren't silica based. However, I was informed by a visitor to my website that I had made an error identifying a mineral specimen I had gotten in trade. I called it a thunderegg because that's what I always called solid "geodes". Apparently thundereggs are formed in volcanic areas, technically speaking. It was a yellowish mineral that if I had soaked it in oxalic acid might have turned to calcium oxalate. Which was the chemical composition of my kidney stone. Everything comes around in a circle.