Likely fireblight. Cut the whole branch out.

Take it back to where you purchased the plant. I also take off any branches that had previously flowered. I also start exta backup plants. I also grow them in pure pumice to keep them dry enough, this year I added coarse sand. Some will grow in open run in hot desert areas. My Tromotriche engieriana has just come into flower, and I do believe they are winter growers. This flower is a magenta black tulip shapped and hangs down. I do see new growth starting at this time. Watch for mealies they hang out in the center of the growth. I don't see any rot at this time of the year. I also don't see any of the Stapelia in flower at this time, they may flower in November. Thanks, Norma

I'm not an expert in canning but I do know a few things about mechanical engineering. You would need a very high heat to make the bottom weaker. You would also need the inside pressure to be very low. The only way that I could see that happening is if the water evaporated during the canning process and then air wasn't allowed to get air back in the canner. With pressure in the canner it should be totally stable. We actually have used aluminum "ballons" for upper stages of rockets. I guess this could happen if the water boiled off and the weight sealed the vent somehow. If you want to see what happens to aluminium when the temperature get high, go to this link, http://www.grantadesign.com/userarea/mil/mil5.htm on page 3-262. It is slightly different for different aluminiums but basically the strength drops off radically around 300 deg F. That is probably why the makers don't want us to use a big propane burner. Boiling water would increase the pressure until the water was depleated. When the cooling started the thicker metal bottom was hot but the sides started to cool. The pressure in the canner dropped because the temperature dropped. If the vent blocked then a vacuum was created inside the canner. If the canner still had water in it after processing, I have no idea, lol. BTW...having a small burner shouldn't make a difference. Aluminum is a great conductor. Just my $0.02. Rick

Moisture could have been trapped in the unglazed bottom and absorbed into the counter. I wouldn't expect that to be light though unless the counter was waxed or something odd. I would move the bowl for a while and see if it returns to normal. (Doing nothing is always my first plan of attack!) Do you know if the counter has been sealed, or when? If you can post a picture of the damage (or even just the stone because different stones do react differently and someone will probably recognize it) I'm sure you'll get advice. On the bright side, if you can't fix it, you have a fruit bowl that is the perfect size to cover the spot! :P