Honeycomb ruby is a man-made gemstone, not a naturally occurring one, created by layering synthetic ruby pieces in a honeycomb pattern and fusing them together under heat and pressure. This process creates a porous, corundum-like material that shares the same chemical properties as natural ruby but has a distinctive honeycomb structure caused by gas bubbles. It is known for its strong UV reactivity, making it a popular decorative and metaphysical stone.