If a crystal is poping up a lot it might be other sign as well like something to do with your throat chakra. Stones will pop out at us if it's something we need in our lives. A few I know off the top of my head I will share with you. Aqua Aura Quartz, Turquoise, and Azurite.
I would just do more research for yourself on blue stones and crystals...you're intuition will always guide you and you will know which stone or crystal is the one calling to you c:
I hope this helps you and blessed be!