Silicates...

My most recent experiment for 'break like waves' was to try to break rocks in the way that water waves break rocks. I placed gravel from my driveway into a glass goblet and filled with enough water to just cover the rocks. Initially my plan had been to use a can but because glass is more similar to sand and rock I used the glass goblet instead.

The assemblage

             I held the goblet in my left hand and shook it back and forth as I did some reading. The rocks swirl and some water spilled out. After a short time I began to notice differences in the sound of the movement. Instead of just swishing and scraping I began to notice more distinct and isolated sounds, perhaps the sounds of individual rocks striking the sides of the container. It was almost musical. I assume that this was a combination of the reduction in water level, changes in shaking pattern and my brain beginning to tune out the more uniform droning noises.
             After approximately 15 minutes I noticed that I could occasionally feel the glass resonating in my hand. After roughly 20 min I noticed a crack beginning to extend from a chip in the glasses' rim (this was present before the experiment). The water had become opaque and looked like grey milk.
             For the most part the rocks lay in a single layer on the bottom, but occasionally one would jump out of this layer and roll around on top of the others. Sometimes freed individuals would circle around the mass of other stones. These began to occur after approximately 30 minutes.
             After approximately 1 hr. the glass was set down and a new horizontal crack formed.

           There was not much water left in the glass. Water was again added to bring the level again close to the starting amount. The inside of the glass began to be coated with a grey powdery substance, particularly around the rim. During handling an audible 'ping' was heard and it was noted that one of the cracks had expanded. Shaking continued for perhaps another half hour.
           I set the project down for some time while I was at my job and continued it later after work at Ben and Rachel's house. I again refilled the  water and continued agitation for approximately an hour. During this time I did not notice much except that the existing cracks continued to grow.
           I continued again two days later, again refilling the water first. After approximately 45 minutes I noticed that the crack had grown to nearly encircle the goblet. Pieces were  loose and fissures were visibly wider.

Fifteen minutes later several significant pieces of the rim broke off.

The vessel still held the rocks and water so I continued. After about 15 minutes more the remainder of the rim broke off.

I continued agitating and for the next ten minutes rocks fell out of the glass one at a time.

I continued to agitate for some time more. The system appears to have reached a temporarily stable state: there are no visible cracks in the remaining glass and there are less rocks and water contained within. I hypothesize that it would take several more hours before the next dramatic event.