I imagine there are L stones out there with higher silicate content than the average. You were pleased with your stone and the results, and your wife is very happy with her jewelry piece. I am glad for you. I just wish my experience could have been similar. On the surface, the quality Larimar is just really beautiful. The fracturing and the crumbling on the piece I had, although I began with a 600 g. S/C belt, (on a soft drum) with plenty of water did not help much for me. I believe I had an internally flawed piece of stone. Like I said, the stone is the rage at commercial rock shows, and mostly represented by dealers from India. Did not see any D/R - Larimar dealers at Tuscon, so I could talk to them about proper treatment and what they did to bring their stones to shape and polish. I did meet an Ethiopian dealer of Welo Opal at the show. The gentleman was very knowledgeable and helped me to select a couple of really nice stones at a very reasonable price.
I also came away with some very nice boulder opal rough, from an Australian miner selling these stones. Excellent advice about how to cut it, sand, polish, etc. It is a very unusual stone, and I have only had one experience, which came to be a disappointment. After Mr. Cooper's tutorial about proper cutting, sanding and polishing that I got from him, I am anxious to try this again. The name of the mine is Broken River Mining, Queensland, Aus. (Broken River Mining.com) and his wife, Sue Cooper who remained in Australia- supervising mining ( they do not strip it or leave eye sore gouges in the terrain.) Her husband whose first name has left me, gave me encouragement to keep trying as he said that everyone working with this particular type of opal has has a very steep learning curve. I wish there could have been a D/R rep about L. present. Maybe there was. I was not actively looking for L, so that may be the reason?