It is not recommended to wear more than one gemstone at a time. This will not only create conflict but over time the stones will damage themselves by rubbing against each other.
Clear quartz enhances the healing properties of all gemstones, except obsidian. Never wear clear quartz and obsidian together because they will eliminate each other’s working.
Onyx and moonstone aren’t a good match either. Onyx is in fact a compact gemstone which helps you to ‘ground’. Moonstone, on the other hand, is quite the opposite: it is a subtle, creative and expressive stone that enhances your imagination and creativity. A bestower of daydreams if you will.
Tiger’s eye and moonstone go well together because they are both protective stones.
By the way, the gemstone that belongs to your zodiac sign isn’t always the appropriate stone for you. It’s a much better idea to look for a gemstone that can complement some weak characteristics within yourself.