These gemstones have the same physical, chemical, and optical properties as mined gems do. We don’t “make” gems. We control the environment so that crystals can grow naturally: recreating the conditions in which gems grow in the earth.
The process of growing gem crystals in a laboratory rather than mining them is a bit like making ice in your freezer instead of finding it in a lake. You place the starter material, water, in a container, and put the container into a controlled environment: your freezer. Create the right conditions of temperature and time and ice crystals will form. The freezer ice will usually be cleaner and more perfect than lake ice because you can carefully control the environment. But it’s still ice, just like the ice that forms in nature. In a way, what we do is a sophisticated high-tech version of freezing water to form ice.
One of the benefits of lab-grown gemstones is that they have less of an impact on the environment than mined gems.