Ass #17 -Key Terms and Concepts

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Questions and Answers

What is the purpose of annealing in diamond treatment?

To change the diamond's color through irradiation

To improve a diamond's marketability (correct)

To enhance the diamond's clarity through fracture filling

To permanently remove inclusions from the diamond

What characteristic is reported by major gem labs as a result of laser drilling?

The presence of deep inclusions

Refractive index variations

New cleavages created by the laser

Permanent clarity characteristics (correct)

What result does irradiation usually produce in type I diamonds?

A colorless appearance

A blue to green bodycolor (correct)

An orange bodycolor

A pink bodycolor

Which of the following indicates that a diamond has undergone fracture filling?

Trapped gas bubbles, flash effect, flow structure, and a crackled texture. Signup and view all the answers

What happens to the bodycolor of diamonds after HPHT treatment?

It is enhanced by rearranging defects Signup and view all the answers

What is a critical disclosure requirement in the diamond industry?

Disclosing fracture filling treatments Signup and view all the answers

What effect does annealing have on diamonds post-irradiation?

Rearranges color centers Signup and view all the answers

What is the main consequence of laser drilling on a diamond's appearance?

Reduction of visible inclusions Signup and view all the answers

Which type of diamond is likely to produce a pink bodycolor after irradiation and annealing?

Type Ib diamond Signup and view all the answers

How do gemological laboratories assess the color origin of diamonds?

With advanced equipment specifically designed for color analysis Signup and view all the answers

A controlled heating and cooling process is called ?

Annealing Signup and view all the answers

Formation of graphite around a diamond’s mineral inclusions and feathers that results from the extreme conditions of HPHT treatment is...........

Graphitization Signup and view all the answers

A clarity treatment that uses a laser focused on or near an inclusion to enlarge existing cleavages or create new ones, providing a path for a bleaching solution to dissolve the inclusion is .....

Internal Laser Drilling Signup and view all the answers

Spaces in the regular framework of atoms that are usually uninhabited is ......

Interstitial Positions Signup and view all the answers

The definition of Irradiation is....?

Exposure of a material to radiation Signup and view all the answers

Laser drilling can make a diamond ........

more marketable by improving its appearance Signup and view all the answers

Fracture filling makes a diamond’s ......

fractures and cleavages less visible by using a high-RI glass filler Signup and view all the answers

Irradiated diamond color can change if the diamond is .......

exposed to heat during repairs, recutting, or repolishing Signup and view all the answers

The color resulting from irradiation can vary based on ......

the defects already present in the diamond Signup and view all the answers

Irradiation and subsequent annealing of a type Ia diamond creates........

a yellow, orangy yellow, yellow-green, or brown bodycolor. Signup and view all the answers

HPHT color treatment of diamonds uses the same equipment as HPHT diamond growth, but ....

at slightly different pressures and temperatures Signup and view all the answers

All diamonds need what after HPHT treatment because of the high temperatures and pressures?

repolishing Signup and view all the answers

HPHT processing of type Ia diamonds can enhance color by ........

rearranging vacancies and nitrogen atoms within the crystal lattice Signup and view all the answers

Some treaters use what treatments to achieve the desired bodycolor?

a combination treatments Signup and view all the answers

HPHT treatment of type II diamonds can enhance color by ....

removing vacancy clusters that cause a brown or gray bodycolor Signup and view all the answers

What were one of the earliest methods of diamond color modification?

Coatings Signup and view all the answers

Modern silica coatings are fairly durable ........

but not permanent. Signup and view all the answers

Study Notes

Annealing and Graphitization

Annealing is a controlled heating and cooling process.
Graphitization forms graphite around diamond inclusions from high-pressure, high-temperature (HPHT) treatment.

Laser Drilling

Laser drilling improves diamond appearance by targeting inclusions.
It enlarges existing cleavages or creates new ones to dissolve inclusions.
Interstitial positions are spaces in a diamond's regular atomic structure.

Irradiation

Irradiation exposes a diamond to radiation.
It can change a diamond's color based on existing defects.
Type I diamonds irradiated become blue to green.
Subsequent annealing can further change the body color of a diamond.
Type Ia diamonds become yellow, orangy yellow, yellow-green, or brown.
Type Ib diamonds are pink.

Fracture Filling

Fracture filling reduces visibility of fractures and cleavages with high-refractive-index (high-RI) glass.
Signs include flash effect, trapped gas bubbles, flow structure, and crackle texture.

Diamond Color Modification

Disclosure of fracture filling is required information in diamonds.
Heat exposure (during repairs, recutting, or repolishing) can change irradiated diamond color.
HPHT treatment can rearrange defects in the crystal lattice.
HPHT treatment needs repolishing due to high temperatures and pressures.
HPHT treatment of Type Ia diamonds enhances color by rearranging vacancies and nitrogen.
HPHT treatment of Type II diamonds removes vacancy clusters to reduce brown and gray coloration.
Combination treatments improve desired body color.
Coatings were early methods, though modern silica coatings are durable but not permanent.

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Description

Explore the various processes involved in diamond treatments, including annealing, graphitization, laser drilling, and irradiation. Understand how these techniques enhance diamond appearance and alter their properties. Learn about the effects of fracture filling and the visual indicators of treated diamonds.