Intricately Detailed 3D Rendering of Four Exquisite Gemstones

Create an intricately detailed 3D rendering of four exquisite gemstones arranged in a symmetrical 2x2 grid, each gem in direct contact with the others. The perspective is a dramatic top-down view. One gemstone features a radiant emerald cut, exhibiting a transparent aqua-blue tone, adorned with an elaborate silver engraving of the word "Serenity." The other three gems display the colors deep crimson, royal purple, and crystal-clear diamond. One includes an ornate golden design resembling flowing vines, while the remaining two showcase inscriptions of "Unity" and "Grace" in refined carved lettering. Ensure realistic polished surfaces with subtle refracted light effects, delicate sparkling accents, soft shadow gradients, and an elegant velvet-textured background in luxurious midnight blue.