The main medium used in this work is polymer clay. Polymer clay is not a traditional earthen clay, but a low-T cure thermoset polyvinyl chloride (PVC). It's malleable prior to curing, hence the designation as a "clay". It comes in a variety of colors that can be mixed into custom colors.
For the jewelry, the cured clay elements are mixed with a variety of materials such as gemstones, handmade glass elements, and both precious and base metals.
Polymer clay can be worked like a regular clay-formed into shapes, textured, etc. However, polymer clay has some unusual properties that are not present in earthen clay materials. The color palette is nearly unlimited, the "metallic" clays have mica shifting properties, and the low firing temperature makes it accessible without any special equipment. The versatility of this medium means that techniques from a variety of disciplines can be imitated including (but not limited to) lapidary, ceramics, metalworking, and glassworking techniques.