Emerald

Emeralds are a desirable gemstone that are formed deep within the Earth through a process involving heat, pressure, and the presence of specific elements and other minerals. It is a green variety of mineral beryl (of which aquamarine is a type of blue beryl, and morganite is a type of pink beryl). A green beryl becomes an emerald when it's colour becomes so saturated and intense (caused by traces of vanadium or chromium in it, along with sometimes traces of iron, which can impart a more blue-green tone), that gemological institutions and jewellery industry practice determine that  a particular shade of green beryl is now good enough to be classed as 'emerald' shade (there are colour grading charts for this) and so it becomes an emerald. All emeralds are green beryls, but not all green beryls make the 'grade' to be called emeralds. I actually love green beryls as much as emeralds - their shade is a gorgeous pastel or pale mint green colour (due to only smaller amounts of chromium or vanadium in it) and you do see them set occasionally set into jewellery.

Emeralds can form in various geological settings. Most well known is emerald formation in pegmatites, which are coarse-grained igneous rocks. The beryl mineral in these pegmatites interacts with elements like chromium or vanadium during the cooling process, leading to the formation of emerald crystals. Emeralds are also associated with metamorphic rocks such as schist and gneiss; the heat and pressure in these rocks provide an environment where beryl can transform into emerald. Hydrothermal processes, involving hot fluids moving through rocks, can contribute to emerald formation; these fluids carry elements that influence the colouration of beryl, resulting in the creation of emerald crystals in fractures or voids. Finally, over time, emeralds can be weathered out of their original rocks and transported to alluvial deposits, such as river gravels, where they accumulate and can be picked from the river itself. The captivating journey of emerald formation showcases the dynamic processes within the Earth's crust over geological time.

Emeralds are probably the world's best known green gemstone and revered by royalty for their rarity and beauty throughout the world for millennia. Noticeable inclusions and surface marks are normal and expected, so they usually receive a treatment called 'oiling' (or occasionally filling with resin) to create a smoother and more aesthetically pleasing stone - unoiled or untreated emeralds are uncommon and sought after. Emeralds are a traditional birthstone of May, and also a 20th,  a 35th and 55th anniversary stone. 

Emerald care: to keep this gorgeous gemstone in good condition for years to come, it's best to store it away from harder gems (such as diamond, sapphire or ruby) to avoid it being scratched. It also benefits from being wrapped up well when not in use, as some types of emerald will fade if kept in direct sunlight for a long period of time. Emerald can be cleaned by gently wiping it with a damp cloth, drying immediately afterward. Avoid exposing it to heavy knocks as this may crack the stone.