Featured topics:

The fundamental mineral classification of emeralds within the broader beryl family.

In this lesson:

• How minerals form in nature
• The beryl mineral species
• Different varieties of beryl
• What makes ...an emerald

Highlights:

• Emerald is the vibrant green variety of beryl coloured by chromium and vanadium, with a hexagonal crystal structure.
• Pure beryl is completely colourless (known as goshenite).
• Trace elements (<1%) dictate variety: chromium and vanadium make emerald; other trace elements result in aquamarine, morganite, or heliodor.
• Beryls are ideal jewellery gemstones due to their stable colour, high transparency, and large crystal sizes.

Takeaways:

• Emeralds are not a unique species, but a trace-element variant of the beryl family.
• Emerald, ruby, and sapphire comprise "The Big Three" in coloured gem history.

Glossary - Lesson 2

Mineral: An inorganic substance with a defined chemical composition and crystal structure.

Crystal structure: The repeating atomic arrangement of elements within a mineral.

Chemical element: A chemical substance consisting of only one type of atom, such as beryllium, chromium, iron, or vanadium

Beryl: The mineral species from which emerald, aquamarine, morganite and other varieties come.

Emerald: The green variety of beryl coloured primarily by chromium and vanadium.

Goshenite: Colourless beryl.

Trace elements: Minor chemical elements present in very small quantities that strongly influence colour.

Aquamarine: The blue variety of beryl.

Morganite: The pink variety of beryl.

Heliodor: The golden-yellow variety of beryl.

Hexagonal crystal system: The crystal system in which beryl forms.