Only some gems require special care, but all jewelry with stones requires basic care, such as avoiding impacts against hard surfaces, sudden temperature changes, etc.
The settings are particularly vulnerable and should be checked periodically to ensure they continue to fulfill their function.
To clean crystalline stones, it is sufficient to use soap and water and rub them with a soft brush. Diamonds, sapphires, and rubies can be cleaned with ultrasound or in a solution with a little ammonia, but many other stones, such as emeralds, could be damaged.
Opaque gems such as lapis lazuli or turquoise require special care, since, being porous, they can absorb cleaning products and change color. Therefore, it should be enough to rub them with a soft cloth.