Resin is a durable and transparent plastic that is especially suited for jewelry-making because of its ease of use. It begins in a liquid form, but after being casted, becomes quite durable. Special resin molds with smooth surfaces are created to give it a glossy finish.
Marcasite The mineral marcasite, sometimes called white iron pyrite, is iron sulfide (FeS2) with orthorhombic crystal structure. On fresh surfaces it is pale yellow to almost white and has a bright metallic luster. It tarnishes to a yellowish or brownish color and gives a black streak. It is a brittle material that cannot be scratched with a knife. It typically forms under low-temperature highly acidic conditions.