Diamond Treatments

DIAMOND TREATMENTS: WHAT YOU SHOULD KNOW BEFORE YOU BUY

A beautiful diamond can have a little more to its story than meets the eye.

Some natural diamonds undergo treatments designed to improve their color or clarity. A treated diamond isn’t necessarily something to avoid, but it’s important to know what treatment was performed, whether it is permanent, how it affects care, and whether the price reflects it.

Here are five common diamond treatments and what you should know about each one:

HPHT — High Pressure, High Temperature

What is it?

HPHT treatment exposes a diamond to extremely high pressure and temperature to alter its crystal structure and improve or change its color. It can be used to reduce certain brownish tones or produce other desirable colors.

The Pros:

• The color change is generally considered permanent under normal wear.

• It can dramatically improve a diamond’s appearance.

• It can offer an attractive diamond at a different price point than a comparable naturally colored stone.

The Cons:

• The resulting color is treated, not naturally occurring.

• Treatment can affect the diamond’s market value compared with an otherwise comparable untreated diamond.

• Specialized testing may be necessary to identify HPHT treatment.

What to avoid:

Avoid purchasing an HPHT-treated diamond that is being represented or priced as though its color occurred naturally. Look for treatment disclosure and, for a significant purchase, an independent laboratory report that clearly identifies the diamond and any detectable treatment.

IRRADIATION

What is it?

Irradiation exposes a diamond to controlled radiation to alter its color. Additional heat treatment, known as annealing, may then be used to create or modify colors such as blue, green, yellow, or other hues.

The Pros:

• Can create striking fancy-color appearances.

• Makes colorful diamonds available at prices that can be substantially different from rare diamonds with naturally occurring fancy color.

• The treatment can produce beautiful, vibrant results.

The Cons:

• The color is treated rather than naturally occurring.

• Some treated-color diamonds may require special consideration during jewelry repair because excessive heat can potentially alter their color.

• Their value is generally different from that of comparable natural-color diamonds.

What to avoid:

Never assume a vivid color is naturally occurring simply because the stone is a natural diamond. Ask specifically whether the color is natural or treated. Before repair or resizing, always tell your jeweler that the diamond has been treated so appropriate precautions can be taken.

FRACTURE FILLING

What is it?

Fracture filling improves the appearance of certain surface-reaching fractures by filling them with a glass-like substance. This makes the fractures less visible and can make the diamond appear clearer to the eye.

The Pros:

• Can noticeably improve the appearance of a heavily included diamond.

• May make a larger or more visually appealing diamond available at a lower price.

The Cons:

• Unlike the diamond itself, the filling is not permanent or equally durable.

• Heat, chemicals, and some cleaning or repair procedures can damage or alter the filler.

• The diamond’s apparent clarity after filling does not represent its untreated clarity.

What to avoid:

This is one treatment where care is especially important. Avoid exposing a fracture-filled diamond to high heat, harsh chemicals, acids, or ultrasonic cleaning unless a knowledgeable jeweler confirms it is safe. Always disclose the treatment before having the jewelry repaired, cleaned, sized, or worked on.

 

LASER DRILLING

What is it?

Laser drilling uses a very small laser-created channel to reach certain inclusions inside a diamond. The inclusion can then be removed or made less noticeable, improving the diamond’s appearance.

The Pros:

• Can make dark or obvious inclusions significantly less noticeable.

• The laser channel itself is permanent.

• Can improve the face-up appearance without filling the diamond with a foreign material.

The Cons:

• The diamond has still undergone clarity enhancement—the original inclusion and/or evidence of treatment may remain.

• Laser drill channels can sometimes be visible under magnification.

• A laser-drilled diamond should not be valued as though it achieved its appearance without treatment.

What to avoid:

Avoid paying an untreated-diamond price for a laser-drilled stone. Ask whether any clarity enhancement has been performed and review the laboratory report when available.

Also ask whether the diamond has only been laser drilled or has also been fracture filled, because the latter requires additional care.

 

SURFACE COATING

What is it?

A very thin artificial coating is applied to all or part of a diamond’s surface to alter or improve its apparent color.

The Pros:

• Can create an attractive color or mask an undesirable tint.

• Can produce a dramatic visual change without altering the entire internal structure of the diamond.

The Cons:

• The coating is not necessarily permanent.

• It may scratch, wear away, or be damaged by heat, chemicals, polishing, or routine jewelry work.

• If the coating changes or wears off, the diamond’s appearance can change significantly.

What to avoid:

Avoid abrasive cleaning, polishing, excessive heat, and harsh chemicals on a coated diamond, and always tell your jeweler about the treatment before service or repair.

 

THE GOLDEN RULE

A diamond treatment isn't automatically a bad thing. An undisclosed treatment is.

Treatments can make beautiful diamonds accessible at different price points, but you deserve to know exactly what you're purchasing.

Before buying, ask:

• Is the diamond treated?
• Is the color or clarity natural or enhanced?
• Is the treatment permanent?
• Does it require special care?
• Is the treatment disclosed on the laboratory report?

Knowledge gives you the confidence to choose the diamond that's right for you, and to care for it properly for years to come.

Have questions about a diamond?

Come in and see us! We’re always happy to help you understand exactly what you’re looking at before you buy!