Diploma Chapter 13 Gem Treatments Study Notes

These flashcards cover key concepts, terms, and definitions related to gemstone treatments, heating, diffusion, and irradiation.

Heating

A process that can produce or remove color and inclusions in gemstones.

Diffusion

The process of introducing color into gemstones by allowing certain elements to penetrate their crystal structure.

Irradiation

A treatment method that exposes gemstones to radiation to alter their color, which can sometimes be reversed.

Corundum

A mineral form of aluminum oxide, which includes gemstones such as sapphire and ruby.

Lattice diffusion

Deep penetration of color-causing elements into the gemstone's internal structure.

Fe²⁺

Ferrous iron; its presence contributes to the darker blue color in sapphires.

Fe³⁺

Ferric iron; this form can become Fe²⁺ through heating, influencing color intensity.

Maxixe Beryl

A type of beryl that has a deep blue color due to irradiation, which fades after exposure to light.

Charge transfer

The process by which electrons move between ions, affecting the color of gemstones.

Amethyst

A variety of quartz that appears purple due to the presence of iron and its ionic states.

Blueberry Quartz

A type of quartz that appears violet-blue, formed from heat and gamma irradiation of prasiolite.

HPHT treatment

High Pressure High Temperature method used to create permanent color changes in diamonds.

Type IIa diamonds

Diamonds with very low nitrogen content, often subjected to HPHT treatment for color improvement.

Star sapphires

Sapphires that display a star-like pattern, formation encouraged by slow cooling which promotes rutile crystallization.

Electron bombardment

A method of irradiation used in diamonds that creates colors by displacing carbon atoms in their structure.