Emerald is a precious stone with countless virtues, and is just as fascinating as diamonds. Like many people, you probably wear this gem on your jewelry (necklaces, rings, bracelets… faceted or cabochon) without having any idea of its origin. Planetys helps you find out more about the formation of emerald.
The origins of emerald
Emerald is called a hydrothermal gem because it is formed in hydrothermal springs. Hydrothermal springs are reservoirs of hot water found at depths of between 500 and 5,000 meters on ocean ridges. These are precisely where two tectonic plates diverge. Emerald is formed as magma rises through the rock.
The elements that make up emerald normally come from different geochemical sites. The chromium, iron and vanadium found in emerald are constituents of the earth’s mantle. Beryllium and alkalis, on the other hand, are elements of the continental crust. As magma rises, these different emerald constituents come together at the openings between tectonic plates. This is where the magma cools.
A coveted stone since antiquity, the first emerald was discovered in Egypt. Today, the majority of stones found on the world jewelry market come from Colombia. Haute joaillerie jewels like those offered by Planetys also feature emeralds from Brazil, Pakistan, Zambia, Zimbabwe, Afghanistan, Russia…
Stones from the Muzo deposits in Colombia are formed in the Cordillera Oriental basin. Brazilian emeralds are produced in phlogopite rocks (phlogopitites) and plagioclase rocks (plagioclasites).
How is emerald formed?
Like aquamarine, emeralds belong to a family of minerals known as beryls. They are formed by the fusion of beryllium, silicon, aluminum and oxygen molecules during the cooling of magma. As these elements fuse together, they form hexagonal beryl crystals. Basically, they are mostly transparent, but the presence of certain metals gives them a specific color.
Emerald is the green variety of beryl. It contains chromium, vanadium and iron, which give it its green color. When the mineral formed is not of a bright, intense green hue and low refraction, it is simply referred to as green beryl. The beryllium in emerald is responsible for its structure. Whatever its clarity, this gemstone often contains inclusions, despite its rarity.
What accounts for the appearance of the different emerald variations?
How do you explain the appearance of different emerald colors? The color of a stone depends on the amount of trace metals it contains. In the case of this stone, it’s the proportion and distribution of chromium, vanadium and iron that determine its hue. The different concentrations found in gems lead us to distinguish three main categories of stones:
- yellow-green emerald
- green-blue emerald
- pure green emerald
The green color of emerald is obtained by a reaction between chromium and vanadium. When the quantity of one of these metals is low in a stone, its green color turns to yellow. Yellow-green stones are rarely used to make jewelry, as they are not very valuable.
When the amount of iron in a stone is significant, its color turns to shades of blue. Blue-green emerald is darker than pure green stones. A gemstone with a more or less equitable proportion of chromium and vanadium and a small amount of iron has a pure green color.
It’s this emerald that we use in fine jewelry to make top-quality pieces. These intense green gemstones have great purity and look even better after cutting. We use them to make earrings, rings, necklaces and bracelets that enhance your style. Find our collection of emerald jewelry at the best prices on our online boutique.
