I didn't get a photo of just the sand mold, but when you scroll down to the bottom you'll see it. Basically, to sand cast you could just dig a hole in sand, and pour glass into it. It can be that simple!
First you have to get all suited up. Charlotte has her casting jacket on (a lot of people wear them backwards), as well as a mesh face mask, jeans, running shoes (I burned a hole in my favorite boots two weeks ago from stepping on hot glass), and gloves that you can't see.
Here you can see the giant kevlar glove on Charlotte's hand that is protecting her from a very hot furnace that's full of molten glass. I'll assume it's around 2000°C, but to be honest I always forget which furnace is which temperature (there's a second cooler one in the background for blowing).
After gathering your ladle, you pour out your molten glass! You want to do it as fast as you can, but without tipping your ladle past the 90° point. The inside of the ladle is lined with glass that has already cooled off a lot, so if you tip too far, all that 'cold' glass will fall out and make a mess.
That's all you need to know to understand the basics of sand casting! It can be an extremely technical and intricate form of glass art though. There's adding color, inclusions, different annealing programs, manipulating the hot glass, and more. We also mix the sand and water with different substances to cause different results, and we even mix different sand for different results!
... Kind of like professional sand sculptors on the beach, the reason they're so detailed and amazing is because they truck in different types of sand, with different properties.
Bet you didn't know all that about sand, did you?