By Dr A. Barnard, PhD (Geology)
Introduction
The words we use, our scientific lexicon, are among the most powerful tools in science. Every scientific discipline depends upon carefully defined terminology that allows researchers around the world to communicate with precision. A chemist, physicist or geologist should be able to read a scientific paper written decades ago and understand exactly what the author meant.
Mineralogy is no different.
Words such as mineral, rock and crystal are not merely descriptive; they each carry very specific scientific meanings. Yet outside geology these words are often used much more loosely. Jewellery, gemology and everyday conversation have evolved their own vocabulary, and those definitions do not always align perfectly with those used in Earth science.
At Gemdrop, we believe scientific precision matters.
That doesn't mean one vocabulary is "wrong" and another is "right." It simply means that different disciplines sometimes use the same words in different ways. As a company founded by a geologist, we have chosen to adopt terminology that follows classical mineralogy as closely as possible.
One example is our deliberate use of the word gem rather than gemstone when referring to laboratory-grown materials.
To understand why, we first need to answer a surprisingly simple question.
What is a mineral?
A mineral is traditionally defined as:
A naturally occurring, inorganic solid with a definite chemical composition and an ordered crystalline structure.
Although this definition appears straightforward, each part is important.
Naturally occurring
A mineral must form through natural geological processes.
Quartz growing inside a hydrothermal vein, diamond crystallising deep within the Earth's mantle and calcite precipitating from groundwater all qualify because nature produced them.
If humans manufacture the identical material in a laboratory, however, it is no longer considered a mineral under the classical geological definition.
Origin matters.
Inorganic
Minerals are generally not produced by living organisms.
Coal, for example, forms from ancient plant material and therefore is not considered a mineral despite occurring naturally.
Solid
Minerals must exist as solids under normal Earth conditions.
Liquid water cannot be a mineral.
Definite chemical composition
Every mineral possesses a characteristic chemistry.
Quartz is silicon dioxide (SiO₂).
Corundum is aluminium oxide (Al₂O₃).
Spinel is magnesium aluminium oxide (MgAl₂O₄).
Many minerals allow small amounts of chemical substitution, but each species occupies a well-defined compositional range.
Ordered crystalline structure
Perhaps the most beautiful feature of minerals is that their atoms are not randomly arranged.
Instead, they occupy precise positions within a repeating three-dimensional crystal lattice.
This invisible atomic architecture controls nearly every property we observe, from hardness and cleavage to refractive index, birefringence and crystal habit.
It is the crystal lattice that transforms chemistry into beauty.
The curious case of ice
One of the most famous examples used in mineralogy classrooms is ordinary ice.
Snowflakes, glaciers and naturally frozen lakes are all composed of crystalline H₂O.
Because they are naturally occurring, inorganic solids with a crystalline structure and definite chemistry, they satisfy every requirement of the mineral definition.
Natural ice is therefore a mineral.
Now consider an ice cube made in your freezer.
Chemically it is identical.
Its crystal structure is essentially identical.
Its optical behaviour is identical.
Its hardness, density and refractive index are identical.
Yet mineralogists do not classify it as a mineral.
Why?
Because it did not form naturally.
Nothing about the crystal itself changed.
Only its origin changed.
This simple example illustrates one of the most important ideas in mineralogy:
Natural origin is part of the definition of a mineral.
Laboratory-grown gems
Now consider a laboratory-grown ruby.
Modern crystal growth techniques can produce aluminium oxide crystals that are chemically indistinguishable from natural corundum.
The aluminium and oxygen atoms occupy precisely the same crystallographic positions.
Chromium substitutes for aluminium in exactly the same way, producing the same rich red colour.
The hardness remains 9 on the Mohs scale.
The refractive index is the same.
The birefringence is the same.
The specific gravity is the same.
The crystal system is the same.
The optical behaviour is the same.
From the perspective of crystallography, physics and chemistry, laboratory-grown ruby is genuine corundum.
Exactly the same is true for laboratory-grown sapphire, spinel, emerald and many other gem materials.
The atoms do not know whether they were assembled beneath a mountain over millions of years or inside a carefully controlled crystal-growth furnace over several days.
Physics treats them identically.
Mineralogy, however, asks an additional question:
How did the crystal form?
Because laboratory-grown crystals are produced by humans rather than by natural geological processes, they do not satisfy the classical definition of a mineral.
That distinction is entirely one of origin.
It says nothing about their beauty.
Nothing about their quality.
Nothing about their durability.
Nothing about their scientific value.
Why mineralogy still applies
Although laboratory-grown gems are not technically minerals, almost everything we learn about minerals still applies to them.
The principles of crystallography remain unchanged.
Crystal growth follows the same thermodynamic principles.
Atoms occupy the same lattice positions.
Trace elements substitute into crystal structures according to the same chemical rules.
The interaction between electromagnetic radiation and crystal lattices remains identical.
This is where mineralogy and gemology beautifully intersect.
The colours we admire arise because trace elements absorb specific wavelengths of visible light.
Chromium gives ruby its deep red colour.
Iron and titanium produce many blue sapphires.
Vanadium can create emerald's vivid green.
These colours are governed by quantum mechanics and electron orbitals, not by whether the crystal formed naturally or in a laboratory.
The same is true for brilliance.
When light enters a gem it slows according to the material's refractive index.
The geometry of the cut determines how efficiently that light undergoes internal reflection before returning to the observer's eye.
Dispersion separates white light into its constituent colours, producing flashes of spectral fire.
Pleochroism causes certain crystals to display different colours when viewed in different crystallographic directions.
Fluorescence allows some gems to emit visible light after absorbing ultraviolet radiation.
These remarkable optical phenomena arise from crystal structure and chemistry.
Nature and laboratories obey the same laws of physics.
The crystal does not care where it was born.
Rocks, stones and language
If minerals are precisely defined, what about rocks?
A rock is generally defined as:
A naturally occurring coherent aggregate of one or more minerals or mineraloids.
Granite is a rock.
Marble is a rock.
Quartzite is a rock.
Even rocks consisting almost entirely of a single mineral still qualify as rocks.
The word stone, however, is different.
Unlike mineral or rock, stone has no universally accepted scientific definition.
Dictionary definitions typically describe stone as a piece of rock, mineral matter, building material, paving material or an individual object such as a precious stone.
An interesting pattern emerges.
In dictionary definitions the word stone almost always reflects a human perspective.
We build with stone.
We pave roads with stone.
We carve stone.
We collect stones.
We set stones into jewellery.
By contrast, geologists study rocks.
Although many people naturally speak of finding a stone on a beach or throwing a stone across a river, the word itself often carries the sense of something selected, handled, worked or considered by people.
Why Gemdrop says "gems"
Within modern gemology and the jewellery trade, terms such as synthetic gemstone and laboratory-grown gemstone are widely accepted and perfectly understood.
At Gemdrop, however, we have chosen a slightly different approach.
Because minerals are defined by natural origin, and because gemstones have traditionally referred to natural mineral materials used in jewellery, we reserve the word gemstone for naturally occurring gem materials.
Laboratory-grown materials are simply gems.
This is not because they are inferior.
Far from it.
Laboratory-grown gems are genuine crystalline materials possessing the same chemistry, crystal structures, optical properties and physical behaviour as their natural equivalents.
Our terminology simply reflects the mineralogical distinction between naturally occurring minerals and their laboratory-grown counterparts.
It is a small linguistic choice, but one that reflects our commitment to scientific precision.
Looking to the future
Humanity has become remarkably good at growing crystals.
Processes such as Verneuil growth, Czochralski pulling, hydrothermal synthesis, flux growth, HPHT and chemical vapour deposition continue to advance every year.
Crystals become larger.
Purity improves.
Defects decrease.
Colour becomes more precisely controlled.
Entirely new materials become possible.
Many of the challenges that limited crystal growth only a generation ago have already been overcome.
Many more will disappear during the decades ahead.
As crystal engineering continues to mature, laboratory-grown gems will become increasingly sophisticated, allowing gem cutters, jewellers, artists and collectors access to extraordinary materials that previous generations could scarcely imagine.
Nature will always inspire us.
After all, every laboratory-grown crystal owes its existence to principles first demonstrated by geology over billions of years.
Yet laboratories now allow us to understand, reproduce and refine those same processes with astonishing precision.
Conclusion
The distinction between a mineral and a laboratory-grown crystal is not a question of authenticity, beauty or quality.
It is simply a question of origin.
Minerals form naturally.
Laboratory-grown crystals are produced by people.
Everything else, the crystal lattice, chemistry, hardness, refractive index, brilliance, fire and interaction with light, remains fundamentally the same.
At Gemdrop, we celebrate both.
Our choice to describe laboratory-grown materials as gems rather than gemstones reflects our background in geology and our commitment to scientific precision.
Words matter.
Science matters.
And perhaps the greatest lesson of all is that whether grown deep within the Earth or carefully cultivated inside a modern crystal-growth laboratory, the extraordinary beauty of crystals reflects the same elegant physical constants.