If a treasure hoard includes gemstones, you can use the following tables to randomly determine the kind of gemstones found, based on their value. You can roll once and assume all the gems are the same, or roll multiple times to create mixed collections of gemstones.

500gp Gemstones:
d6 = 2

Aquamarine (transparent pale blue-green)

500gp Gemstones
d6500gp Gemstones
1Alexandrite (transparent dark green)
2Aquamarine (transparent pale blue-green)
3Black pearl (opaque pure black)
4Blue spinel (transparent deep blue)
5Peridot (transparent rich olive green)
6Topaz (transparent golden yellow)