Turquoise is a soft mineral, and the hardness of gem-grade turquoise is only 5~6 on Mohs hardness scale, so it is relatively easy to wear. 18K gold is a mixture of pure gold and other metal alloys, which is more durable than 24K pure gold. Therefore, the use of 18K gold buckle can better protect turquoise and avoid wear and damage.

In fact, different jewelry designers and jewelers may use different materials for different buckles to achieve different aesthetic effects and usage requirements. Therefore, if you want to buy or make a turquoise jewelry, it is recommended to consult a professional jewelry designer or jewelry dealer to provide you with better suggestions and choices.

In a word, turquoise can be buckled with 18K, which can better protect turquoise ornaments and make them more durable. But the specific collocation method needs to be selected according to different designs and requirements.