MIRA Ginza
1040061
Mikuni Ginza 7 Building 1F, 6-11 Ginza 7-chome, Chuo-ku, Tokyo
Business hours: 11:00-20:00
Closed: New Year's holidays
A lab-grown diamond is a diamond.
A lab-grown emerald is an emerald.
Same gemstone.
Different origin.
They share essentially the same chemical composition, crystal structure, and physical and optical properties as their natural counterparts. What distinguishes them is not what they are, but where and how they are formed.
Natural gemstones grow within the Earth over immense spans of geological time. Lab-grown gemstones are created in controlled environments that reproduce the conditions required for crystal growth.
They are not imitations.
They are gemstones of a different origin.
The difference between a natural gemstone and its lab-grown counterpart begins with its origin.
A natural diamond forms deep within the Earth under extraordinary heat and pressure. A lab-grown diamond is created by reproducing the conditions that allow carbon atoms to crystallize into diamond.
The result is the same fundamental material: crystalline carbon.
The same principle applies to colored gemstones. A lab-grown emerald has the same essential chemical composition and crystal structure as natural emerald. Lab-grown ruby and sapphire, like their natural counterparts, are forms of corundum.
This is why gemological institutions distinguish lab-grown gemstones from gemstone simulants.
The essential difference is origin — not identity.
The word “laboratory” can sometimes create the impression that a gemstone is artificial or merely resembles the natural stone. That is not the case.
A diamond simulant is a different material designed to resemble a diamond. Cubic zirconia and moissanite, for example, may share some visual characteristics with diamond, but they have different chemical compositions and physical properties.
A lab-grown diamond, by contrast, is diamond.
| Natural Diamond | Lab-Grown Diamond | Moissanite | Cubic Zirconia | |
|---|---|---|---|---|
| Material | Diamond | Diamond | Silicon Carbide | Zirconium Oxide |
| Main Composition | C | C | SiC | ZrO₂-based |
| Mohs Hardness | 10 | 10 | 9.25 | Approx. 8.5 |
| Origin | Earth | Laboratory | Laboratory* | Laboratory |
*Gem-quality moissanite used in jewelry is generally laboratory-created.
Lab-grown is an origin. Imitation is a different material.
There are two principal methods used to grow gem-quality diamonds today: HPHT and CVD. Both begin with the same idea: create an environment in which carbon can develop into the crystal structure of diamond.
HPHT recreates the intense pressure and temperature associated with diamond formation deep within the Earth.
A small diamond seed is placed together with a carbon source inside a specially engineered growth environment. Under extreme heat and pressure, carbon crystallizes around the seed, gradually forming a diamond.
A thin diamond seed is placed inside a controlled chamber containing carbon-rich gas. With carefully controlled energy, carbon atoms are released from the gas and deposited onto the seed, layer by layer, allowing the diamond crystal to grow.
Different process.
Same remarkable crystal.
Technology does not imitate the appearance of a diamond. It creates the conditions in which diamond can grow.
MIRA works with lab-grown colored gemstones including emeralds, rubies and sapphires — gemstones grown with the same essential chemical composition and crystal structure as their natural counterparts.
Both natural and lab-grown emerald belong to the beryl family. Their essential chemical composition is:
Their green color comes from trace elements incorporated into the crystal as it grows. Natural emeralds form through complex geological processes and are often characterized by inclusions and fissures created during their formation. Lab-grown emeralds grow under more controlled conditions, allowing exceptional color and clarity to be achieved.
But both are emerald.
Ruby and sapphire are both varieties of the mineral corundum, whose principal chemical composition is:
Different trace elements within the crystal produce their extraordinary spectrum of color — from the intense red of ruby to royal blue, pink, yellow and many other shades of sapphire.
Whether formed within the Earth or grown in a laboratory, their identity as corundum remains the same.
For MIRA, lab-grown gemstones are not a substitute for something else. They are a creative medium in their own right.
Fine jewelry has long been shaped by rarity. Extraordinary colors, exceptional clarity and significant carat weights in natural gemstones can be exceedingly scarce.
Lab-grown technology opens another possibility.
It gives our designers greater freedom to explore scale, color, proportion and unexpected combinations — allowing the gemstone to serve the idea, rather than asking the idea to conform to scarcity.
A vivid emerald in an unapologetic scale.
A constellation of sapphires in precisely considered shades.
Diamonds cut into forms created specifically for a MIRA design.
Not a lesser version of the past, but a new possibility for fine jewelry.
Lab-grown does not mean uniform. Just as natural gemstones vary in color, clarity, cut and beauty, lab-grown gemstones vary significantly in quality.
For MIRA, origin is only the beginning. Every stone is considered for its color, clarity, proportions, cut and — most importantly — the way it performs within a finished piece of jewelry.
For round brilliant diamonds, MIRA selects stones meeting exacting standards for cut, polish and symmetry. Main diamonds are selected for exceptional visual clarity and brilliance.
For colored gemstones, color is paramount. We seek vivid, sophisticated hues and carefully consider tone, saturation, clarity and the relationship between every stone within a composition.
We select for beauty.
MIRA believes that the origin of a gemstone should never be ambiguous.
Our gemstones are clearly disclosed as laboratory-grown, and eligible pieces are accompanied by independent gemological documentation, including IGI reports where applicable.
IGI uses advanced gemological testing to determine whether a diamond or gemstone is natural, laboratory-grown or a simulant.
In addition, every MIRA creation is accompanied by a MIRA certificate bearing its unique identification number — our record of the piece and its specifications.
Because a new kind of luxury should begin with clarity.
