Citrine

Citrine is a type of quartz and is known for its warm, golden-yellow to brownish hues. Most natural citrine comes from Brazil, though it can also be found in other parts of the world, including Madagascar and the U.S. Often, citrine is heat-treated amethyst or smoky quartz. The heating process transforms the color from purple or brown to the yellowish hues associated with citrine. This means it's fairly durable and suitable for various types of jewelry, though it can still be scratched by materials with a higher hardness. Citrine ranks 7 on the Mohs scale of mineral hardness.