Swarovski Crystal Pearls are made with a crystal core. The mother of pearl-like layers are then applied evenly to the core which ensures harmonious tones and color matching. The surface finish is consistent and gently reflects light to create an irresistible appeal. They are resistant to wear, the sun's rays, perspiration and perfume to retain their shimmer for a very long time. HOLE SIZE ON THESE IS 0.9 MM. What is the secret of Swarovski Crystal Pearls? The unique Swarovski Crystal Pearl technology. Each Swarovski Crystal Pearl is created around a crystal core, hence the name Crystal Pearl. This crystal core gives the pearl its ideal weight and combined with the Swarovski Pearl coating it causes each Crystal Pearl to glow from within. The pearl coating developed by Swarovski is applied around the crystal core in pearly layers.