What is the primary function of a lap horizontal in gem processing?

The primary function of a lap horizontal in gem processing is to grind or polish a gem's facets. This tool is essential in the lapidary process, where precise shaping and finishing of gemstones occur. A lap horizontal is typically a rotating disc that can be coated with various abrasives, allowing gem cutters to create the flat surfaces and precise angles that are crucial for enhancing a gemstone's brilliance and overall appearance.

The polished facets are critical to a gemstone's capacity to reflect and refract light, which is a significant factor in its visual appeal. By ensuring that the facets are ground and polished correctly, lap horizontal tools help achieve the desired level of clarity and shine in the finished gemstone, making this function a key aspect of gem processing.