Sea Glass. i have a lot. I love the stuff. 

Everything I use is actually authentic SF bay glass. And before I glued anything to anything else, I simply....had a lot. I started by gluing little floral crowns of glass to anything- signs, the sidewalk, at a bus stop- basically anywhere where someone might pause and think "....now where did that come from?" I suppose I did this because I am so enamored with the notion of surprise and something unexpected, and pointedly, it does not have to be flashy or glamorous or make a bold statement- better if it is simply an understated, puzzling, possibly even a tiny bit delightful thing. I try to embody this notion in my every day- if I could be said to have a theme or purpose to my being, it would be to make people say "Huh. You don't see that everyday."

So I ran with it for a bit. The spots got more complex, using more glass, plaster casts, acrylic. And, at least in one case, successful. I put one near a friends house, gave her some hints, and she found it, about 2 1/2 years later, strangley beautiful in how much of it had actually eroded, exposing some of the acrylic more deeply embedded in the plaster. And THAT is when I showed her the original video I made, what it looked like years ago, and I told her I would collect my "long game" points either now or in three decades. I can't believe how well that went. 

Some are still out there. Some are gone. All of it was incredibly fun.