1. What Is a Zimmi Diamond?
Zimmi is not a grading term and not a color grade.
Zimmi refers to a specific type of natural fancy yellow diamond rough, commonly recognized in the diamond trade as originating from a particular region and material type. Over time, the name “Zimmi” became associated with rough that produces exceptionally strong and saturated yellow color.
2. Zimmi Is Not a Standard Fancy Yellow
Zimmi diamonds are not standard fancy yellow diamonds and not typical “golden” or canary yellow stones.
Compared to regular fancy yellow or even fancy vivid yellow diamonds, Zimmi material produces a much stronger color intensity.
3. Color Intensity: Stronger Than Fancy Vivid Yellow
Even when compared to Fancy Vivid Yellow diamonds, Zimmi stones often appear more powerful in color.
The material itself allows for deeper saturation, resulting in a bold, almost candy-like yellow that stands out immediately.
4. Color Tones Found in Zimmi Diamonds
Zimmi diamonds are primarily yellow, but often show secondary tones such as:
- Orangy yellow
- Greenish yellow
Among these, orangy yellow Zimmi diamonds are considered rarer and more valuable than greenish yellow variations.
5. Rare Orange Influence and Increased Value
In exceptional cases, Zimmi diamonds can approach yellow-orange or orange tones.
Any visible orange influence significantly increases rarity and price. Stones closer to pure orange are extremely difficult to find and highly sought after.
6. Origin of Zimmi Diamond Rough
Zimmi rough is typically associated with material originating from Sierra Leone and Liberia.
This geographic origin plays a major role in the rough’s structure, color behavior, and cutting potential.
7. Unique Rough Structure
Zimmi rough is usually rounded, smooth, and boulder-like in shape.
This natural formation contributes to the material’s ability to hold color consistently throughout the stone.
8. Cutting Advantages of Zimmi Material
One of the most important characteristics of Zimmi material is how well it retains color during cutting and polishing.
Unlike standard fancy yellow diamonds, where color often escapes through light leakage, Zimmi material keeps its intensity.
9. Why Round Fancy Yellow Diamonds Are Possible with Zimmi
Round fancy yellow diamonds are extremely rare because round cuts tend to lose color.
With Zimmi rough, round brilliant cuts are possible without color loss, and in many cases the round shape enhances the stone’s visual strength.
10. Common Shapes Cut from Zimmi Diamonds
Zimmi diamonds are commonly cut into:
- Cushion cut
- Radiant cut
- Round brilliant
- Pear shape
Each shape maintains strong color presence due to the quality of the rough.
11. Black Inclusions in Zimmi Diamonds
Zimmi material often contains black inclusions.
These inclusions must be removed carefully during cutting, requiring slow and controlled polishing to avoid damaging the stone.
12. Delicate Material and Polishing Risk
Zimmi rough is delicate and sensitive during polishing.
Improper pressure or aggressive cutting can cause fractures or complete breakage. Working with this material requires experience, patience, and precision.
13. Why Zimmi Diamonds Remain Rare
Zimmi diamonds are not mass-produced and are not taking over the market.
Their rarity is due to limited rough supply, difficult cutting, and high rejection rates during polishing.
14. Zimmi Diamonds vs Standard Fancy Yellow Diamonds
Compared to standard fancy yellow diamonds, Zimmi diamonds:
- Show stronger color intensity
- Hold color better in multiple shapes
- Are more difficult to cut
- Are more expensive than regular Fancy Yellow and even many Fancy Vivid Yellow diamonds
The higher price reflects rarity, material quality, and cutting complexity.
15. Working with Zimmi Diamonds at The Diamond Cutter
At The Diamond Cutter, we work with select natural fancy vivid yellow diamonds, including Zimmi material.
Our focus is on stones with exceptional color strength, proper cutting, and long-term value — whether for loose diamonds or custom jewelry projects.
If you are looking for a Zimmi diamond, a rare fancy vivid yellow diamond, or a custom yellow diamond project, feel free to contact us to discuss availability and options.
