 Okay, so this is some sand that I got at the hardware store. Oh, it looks like there are little fragments, few organic fragments in there that are the same color as the bag that it came in. So we have some organic fragments in here. But you'll notice, unlike the previous sample, that this one is almost all the same grain size, and if we use the grain size chart, it looks like it's mostly on the order of the lower medium sand, maybe to the fine sand. One of the reasons that it's so uniform in grain sizes, they actually filtered it. But we would say because it has such a uniform grain size that this sand is well sorted, and that's in contrast to the one here that has a very wide range in grain sizes. So there are specific definitions of well sorted to poorly sorted that depend on that range of grain sizes. The other thing you'll notice is that there are a bunch of different colors of grains. Those are reflecting different minerals. When I look at this in my hand lens, it's mostly quartz, and most of the grains are sub-rounded to well rounded. That indicates that they have been transported some. They weren't directly crushed from rocks. So commercial sand can come from a number of different places, one of which is in river channels, and another is a crushing of a rock into finer pieces. Because there's quite a bit of rounding in these grains, I think that it was collected from an environment that had had some sediment transport, so for example a river channel. The diversity in grain colors, and thus compositions, suggests that it is what we would say a chemically immature rock. As grains are transported, they weather, and more reactive grains react faster. And usually the dark grains have a significant amount of iron and they react faster, whereas the quartz grains are least resistant to that chemical weathering. You can see my video on chemical weathering about those minerals. But the fact that there is a wide range of different minerals, including some that are not very stable, suggests to me that this was near the site of erosion, or in an environment that was fairly dry to reduce the chemical weathering. So you get grains of lots of different sizes. Thanks for watching.