Black, White, and Other Unusual Appearances

Black and white fancy-color diamonds overturn the intuitive rule that diamond color is primarily the result of a single atomic center. In these stones, appearance often arises because countless nanoscale and microscale structures strongly absorb or scatter light.

This is where the boundary between color, transparency, and inclusions begins to blur.

Four Concepts That Must Not Be Confused

Fancy black is a diamond whose dominant perceived appearance is black.

Fancy white is a diamond with a pronounced milky-white, hazy, or opalescent appearance caused by light scattering.

A D–Z colorless diamond is not Fancy white. The trade expression “white diamond” for a D–F stone does not correspond to the formal meaning of Fancy white.

Salt-and-pepper is not a laboratory grade, but a trade description of diamonds in which numerous visible inclusions are part of the intended aesthetic.

[VISUAL 38.1: D-color, Fancy white, Fancy black, and salt-and-pepper—four different concepts]

Fancy Black Is Not a Single Atomic Type

In most natural Fancy black diamonds, the black appearance results from a combination of a very large number of dark crystals and clouds that absorb and scatter light.

GIA studies have identified:

• graphite;
• magnetite;
• hematite;
• native iron;
• other mineral inclusions;
• dense groups of nanometer-scale inclusions.

In a smaller number of cases, the dark appearance may have a different cause, including strong absorption by structural defects or the polycrystalline nature of the material.

The statement “a black diamond is black because of graphite” may therefore be true for an individual stone, but it is not a universal definition.

Factual snapshot—GIA Fancy black research.
In a subset of 1,000 natural Fancy black diamonds, gemologists identified crystalline inclusions as the principal observed cause in approximately 46%, clouds in 43%, and a combination of both features in about 10%. Approximately 1% belonged to the rarer strong-absorption group. This is a laboratory population, not a market statistic for all black diamonds.

Fancy Black and Carbonado Are Not the Same

Carbonado is a natural polycrystalline diamond aggregate with a distinct geologic and textural history, discussed in Chapter 12.

A polished monocrystalline Fancy black diamond may appear very dark, but this does not automatically make its internal structure carbonado.

The difference cannot be determined by sight alone.

Natural and Treated Black Diamonds

Black appearance may be artificially intensified or produced, for example through the creation of graphitized areas along fractures, irradiation, or other processes. Laboratory-grown diamonds may also be very dark.

Opacity is therefore not proof of natural origin, just as visible inclusions are not proof that a stone is untreated.

The complete treatment workflow is reserved for Chapters 57–63; here, one rule is sufficient:

for a Fancy black diamond, material identity and the origin of color/appearance must be confirmed separately.

Fancy White Is Not the “Most Colorless” Diamond

Fancy white arises precisely because a large number of very small structures scatter light within the crystal.

Such a stone may appear:

• milky;
• hazy;
• cloudy;
• opalescent.

This is not the same as a transparent D-color diamond. In the D–Z system, the goal is to assess hue in a transparent stone; in Fancy white, the perception of white results from strong internal scattering.

Nanoinclusions and Dislocation Structures

Research on Fancy white diamonds links their appearance primarily to extremely small inclusions and dislocation loops/structures that may be below the resolution of ordinary optical microscopy.

A cloud that appears only as a milky zone at 10× magnification may therefore have a complex nanostructure.

In a representative GIA group of 400 Fancy white diamonds, 82% were type IaB. This is a strong population association, but it is neither a definition of Fancy white color nor a rule for every individual stone.

Fancy White and the Deep Earth

Type IaB is generally rare among diamonds submitted to GIA. The Fancy white population displays high concentrations of aggregated nitrogen and characteristic hydrogen- and nickel-related systems.

Based on these features and related geologic literature, an important part of the Fancy white population is interpreted as sublithospheric.

But the same limitation applies as with blue diamonds: appearance is not a depth gauge. A superdeep conclusion requires mineral and other independent evidence.

Transparency Is a Separate Axis

For Fancy black, Fancy white, and heavily included diamonds, transparency is often more important in practice than the classic question of “how saturated the color is.”

A stone may be:

• transparent;
• translucent;
• nearly opaque;
• completely opaque under ordinary viewing conditions.

This affects:

• optical character;
• the ability to grade the stone;
• visibility of internal features;
• polishing;
• durability;
• setting method.

Transparency therefore should not be hidden within the single word “black” or “white.”

Salt-and-Pepper, Galaxy, Icy, and Rustic

These terms may be useful as aesthetic or trade descriptions, but they are not standardized laboratory grades.

Two sellers using the expression salt-and-pepper may offer entirely different stones:

• one with many small dark crystals;
• another with large surface-reaching fractures;
• a third with a combination of clouds, naturals, and an irregular cut.

The trade name must therefore be interpreted in terms of the stone’s actual characteristics.

[VISUAL 38.2: Trade name → measurable features: inclusions, transparency, fractures, surface, shape, and treatment]

Bicolor, Banded, and Iridescent Appearances

Some diamonds display clear zones of different color or unusual interference effects.

It is important to distinguish:

• actual body-color zoning;
• localized color associated with radiation;
• reflections from inclusions;
• interference colors in fractures;
• strain-related rainbow graining.

“Rainbows” inside a stone are not automatically a fancy-color phenomenon.

Unusual Appearance and Durability

An alternative aesthetic does not override fracture physics.

In a heavily included Fancy black or salt-and-pepper stone, particular attention must be paid to:

• open fractures;
• cavities;
• chips;
• very thin edges;
• inclusions that break the surface;
• textured facets and localized polishing problems.

This should not be turned into a universal judgment that such diamonds are “weak.” Risk depends on the specific location and geometry of the feature, as will be discussed in Chapters 45 and 47.

Value Is Not a Property of an Inclusion

An unusual inclusion may increase:

• scientific interest;
• aesthetic appeal;
• collector distinctiveness.

But a market premium does not follow automatically.

Value depends on the complete product: identity, appearance, stability, processing, documentation, rarity, demand, and comparable transactions.

Chapter Summary

• Fancy black, Fancy white, D–Z colorless, and salt-and-pepper are not the same category.
• Most natural Fancy black diamonds derive their appearance from numerous crystalline inclusions and/or clouds.
• Graphite is common, but it is not the only cause of black appearance.
• A monocrystalline Fancy black diamond is not the same as carbonado.
• Black appearance may be natural, treated, or present in laboratory-grown material.
• Fancy white is not an extremely colorless diamond; the perception of white results from strong internal scattering.
• Nanoinclusions and dislocation structures are an important part of Fancy white appearance.
• In one GIA research population, 82% of Fancy white diamonds were type IaB; this is not a universal definition.
• Transparency is a separate and important descriptive axis in black/white groups.
• Salt-and-pepper, galaxy, icy, and rustic are trade expressions, not laboratory grades.
• An unusual aesthetic does not eliminate the need to assess fractures, cavities, and surface features.
• Scientific or aesthetic distinctiveness does not guarantee a market premium.

[VISUAL 38.3: Fancy black—crystals, clouds, and rare strong absorption as different paths to a similar appearance]

[VISUAL 38.4: Fancy white—nanoinclusions and dislocation structures that scatter light]