Citrine can be found in Citrine Geodes and you can also get it by smelting amethyst in a blast furnace. It doesn't have other use other than the decorative one.

What kind of wood is the azalea tree made of? Oak? Nope, it's azalea wood!

Golden chain is a decorative block that is crafted from gold (obviously :D) and can be used to craft Golden Chainmail Armor.