What is your favorite type of gem stone or crystal?

I'm a collector and you'll know how expensive opal is, I thought Labradorite was an excellent alternative, (I need to buy more).
That is a very green piece you have there mine is more blue in colour.

I have a labradorite necklace with moonstone and amethyst _(:з」∠)_

I like plain old quartz.

Obsidian and opal

For now moonstone

sugar... 😊

Agate