Bicolor, Parti, and Multicolor sapphires: What are they, what are their differences, and how much do they cost? | Detailed guide
- Carolina Vivas-Serna
- Oct 15
- 7 min read
In the world of corundums, there are sapphires that encapsulate two or more colors in a single gem.
These are bicolor, parti, and multicolor sapphires:
A wonder of nature that offers a unique chromatic spectacle, and turns each stone into a unique work of art.
Want to learn more about these exceptional gems?
So, keep reading this guide we've created for you, where you'll discover:
1. What are bicolor, parti, and multicolor sapphires, and what are their differences?
The terms “bicolor, parti, and multicolor” describe specific characteristics of color zoning in a sapphire.
Color zoning is the uneven distribution of color within a gem, a testament to its natural growth.
See below for each of these categories.
Bicolor Sapphire
Bicolor is the broadest term and refers to any sapphire that clearly displays two colors.
The transition between colors can be gradual or abrupt, and the colors can blend smoothly into an intermediate zone.
Parti Sapphire
This is a specific category within bicolor and multicolor sapphires.
The term "parti" (derived from the English partition) is used to describe sapphires where the color zones are clearly separated, with a sharp line of demarcation.
In these stones, there is no gradual blending: the colors occur in defined blocks or sections.
The blue and yellow parti sapphire is one of the most well-known combinations of this type.
Multicolor Sappphire
Typically, these are sapphires with three or more distinct hues, such as blue, yellow, and green, or even hints of violet.
Below is a table to help you better understand the differences between these types of sapphires:
2. Properties of bicolor, parti, and multicolor sapphires
The fundamental properties of these stones are identical to those of any other sapphire, as they are all corundums:
As you can see, bicolor, parti, and multicolor sapphires have a hardness of 9 on the Mohs scale, like other types of corundum.
This makes them exceptionally durable and suitable for all types of jewelry, including everyday rings.
Their density remains consistent with that of other sapphires, typically ranging from 3.98 to 4.1 g/cm³.
What gives parti, bicolor, and multicolor sapphires their color?
The variety of colors in parti, bicolor, and multicolor sapphires comes from the presence and distribution of trace elements within the crystal lattice:
During crystal formation, the availability of these trace elements changes.
Thus, a higher concentration of iron can result in yellow and green hues; while the presence of iron and titanium produces a blue color.
This means that a blue and yellow parti sapphire is formed in an environment where the concentration of both elements fluctuates.
3. How are bicolor, parti, and multicolor sapphires formed?
Sapphires crystallize from magma rich in aluminum and poor in silicon, or from metamorphic rocks such as marble or gneiss, under high temperatures and pressures.
However, color zoning is the key phenomenon in the formation of bicolor, parti, and multicolor sapphires:
As the corundum crystal grows, it is exposed to a changing geochemical environment.
Fluctuations in temperature, pressure, and the chemical composition of the surrounding fluid or rock dictate which trace elements are incorporated into the crystal structure:
If during a growth phase there is a high concentration of iron and titanium, that layer of the crystal will turn blue.
But if the environment changes and the iron concentration increases, the new growth layer could be yellow or green.
When this process creates clearly defined sections of different colors, the result is a parti sapphire.
If the transitions are slower or the elements blend together, a bicolor sapphire with more diffuse areas is formed.
And if three or more colors are present, a multicolor sapphire is obtained.
4. Where are multicolor, parti, and bicolor sapphires found?
Although multicolor, parti, and bicolor sapphires can be found in many parts of the world, certain deposits are particularly renowned:
Australia: Deposits in Queensland and New South Wales produce stones with classic combinations of blue, yellow, and green, often in intense hues and with very pronounced zoning.
Montana, USA: The Rock Creek and Missouri River deposits are renowned for their beautiful fancy sapphires. Parti and bicolor specimens typically display a color palette ranging from pale blue and mint green to yellow and orange.
Madagascar: This is a very important source of high-quality sapphires in almost all colors. Remarkable bicolor sapphires have been found, often with combinations of blue and yellow, or blue and pink.
Sri Lanka (Ceylon): In addition to its blue sapphires, Sri Lanka also produces bicolor sapphires, which often have very vivid colors.
Tanzania: The Umba River Valley in Tanzania is known for producing an incredible variety of sapphires, including bicolor and color-change sapphires.
5. Are parti, bicolor, and multicolor sapphires rare or expensive?
You should know that parti, bicolor, and multicolor sapphires are considerably rare and can be quite expensive.
Their value can even be higher than some commercial-grade single-color sapphires.
In general, the value of these stones is based on factors such as the following:
Rarity of Formation: The conditions required for a sapphire of two or more colors to form are very specific.
Individuality: When it comes to bicolor, parti, or multicolor sapphires, no two pieces are identical; therefore, they are very attractive to those seeking a unique stone.
Cutting Skill: Cutting a sapphire of this type is an art; therefore, it is important to find a reliable gem cutting service.
Regarding the latter, the lapidary must orient the rough sapphire to best display the color separation.
Sometimes this may mean sacrificing more weight compared to cutting a single-color sapphire, but this complexity can add value to the final gem.
Now, let's talk a little about prices.
The price of a parti, bicolor, or multicolor sapphire can vary greatly depending on the quality of the stone, the supplier, and sometimes the origin.
For example, we have found Australian or Montana parti sapphires of around 1 carat, visually clean and with vivid colors, with prices ranging from €400 to over €2,500 per carat.
We have also seen stones of over 2 carats and of exceptional quality, with prices reaching over €5,000 per carat.
Stones with rarer color combinations, such as blue and violet, can fetch even higher prices.
6. How do you know if a bicolor, parti, or multicolor sapphire is of good quality?
Evaluating the quality of these gems may require the intervention of an expert or gemologist.
But below we share a guide with some key factors you should consider:
7. Fun facts about bicolor, parti, and multicolor sapphires
The color zoning of a parti sapphire is as unique as a fingerprint: it is irrefutable proof of its natural origin, as this growth complexity cannot be replicated in a laboratory to create identical synthetic sapphires.
For gem cutters, this type of sapphire presents an interesting challenge. They must decide between cutting the gem to blend its colors and achieve a uniform hue (such as a blue-green), or cutting it to exhibit the separation of tones, which requires more skill and often results in a smaller but more valuable stone.
Unlike diamonds or blue sapphires, which have famous, named specimens (such as the Hope Diamond or the Logan Sapphire), there is no world-famous parti, bicolor, or multicolor sapphire. The fame of these gems lies in their collective individuality, where each stone is the star of its own story.
For decades, color zoning was seen as an imperfection. However, in recent years, the desire for unique and personalized jewelry has catapulted the popularity of parti sapphires, making them a cutting-edge choice for engagement rings and designer jewelry.
Do you feel you can now make better-informed decisions for your next purchase?
