How can I upcycle a variety of aquarium rocks?

spray paint them and use them to decorate succulents

Spread them on the dirt of inside potted plants.

https://www.fishlore.com/aquariumfishforum/threads/what-to-do-with-old-fish-gravel.372488/

glue them all over outside of lampshade or glass globe; glue them on flower pots;use them as drainage in bottom of planters;glue them on picture frames or mirrors;add them to mosaics;use them to make yourself some colorful new house numbers(glued onto wood numbers); use with resin and put onto tabletop; using cement make colorful stepping stones

I just saw an idea for a 'Rainbow River", you could use something like a split open tube or hose to create a border along a walkway, and fill it with the colorful rocks. They'd also be great covering an old cracked flower pot. Use them in glass jars to place candles or solar lights into. I wonder how they look under a blacklight... ?!

I think to maybe use them and glue them to the outside of unused floral vases or recycled pickle jars, etc. They would make them a colorful statement to hold your fresh flowers.

I think that glueing them on to the outside of an item such as picture frame, mirror, or lampshade would be very impractical, as they would collect lint and dust and make it very hard to keep the it clean.

Use them in a fairy garden as ground cover or to make a trail or walkway to the fairy house.

In another post I found "Resin confetti tray" that looked fun. You could do the same with your rocks I'm sure!