I would definitely purchase a book about the different gems that JTV carries. There are such a wide variety, and colors that may appear to look the same. You need to be able to distinguish between them. There is so much information to learn, where the gems come from, how they are mined, and so on.
Also more gem jars. They cushion your gem, protect them, and display them beautifully. You can study them one at a time, you'll have a perfect view of what's in there. And you can keep your jars in a container that keep them all in one place. If you order enough of them. A case to keep them all on display.
Those are two really important items I would invest in that could really give you a greater advantage to a beautiful collection.