emerald is a gemstone and a type of the mineral beryl colored green by trace amounts of chromium and sometimes vanadium. emerald in antiquity were mined in Egypt at locations on Mount Smaragdus since 1500 BCE.
topaz is a silicate mineral of aluminum and fluorine. topaz crystallizes in the orthorhombic system, and the crystals are often prismatic terminated by pyramidal and other faces.
turquoise is an opaque, blue-to-green mineral that is a hydrated phosphate of copper and aluminum. turquoise has a lower-than-ideal hardness and durability for use in certain types of jewelry.