Citrine is a variety of quartz whose color ranges from a pale yellow to brown due to ferric impurities. Natural citrines are rare, and most commercial citrines are heat-treated amethysts or smoky quartzes.
Resin is a "solid or highly viscous substance," which are typically convertible into polymers. Such viscous substances can be plant-derived or synthetic in origin. They are often mixtures of organic compounds. It is durable and transparent, and starts as a liquid form. After casting, it becomes solid and resilient. Special resin molds with smooth surfaces are created to give it a glossy finish.