The value of a gemstone never depends solely on its gemstone type, but on the individual specimen. Particularly important factors include colour, transparency, clarity, cut, carat weight, rarity, treatment, documentation and - for certain stones - geographical origin.

For coloured gemstones, colour is usually the central factor. An intense, vivid and harmonious colour can make a stone considerably more valuable than a larger specimen with a weaker colour appearance. Transparency and cut are also decisive because they determine how well light, depth and brilliance are displayed within the stone.

No. The size of a gemstone alone does not determine its value.

Especially with coloured gemstones, colour, transparency, clarity, cut and treatment are often more important than size. A small, untreated ruby with intense colour can be considerably more desirable than a larger ruby with weak colour or extensive treatment.

For many coloured gemstones, colour is the most important value factor. Hue, intensity, saturation and evenness are decisive. A vivid, harmonious and natural colour makes a stone particularly attractive.

For example, an intense red is sought after in ruby, a clear and vivid blue in sapphire, and a fine, rich green in emerald. Rare colours such as padparadscha, teal, neon blue, cobalt blue or mandarin orange can also be particularly desirable.

Transparency describes how much light passes through a gemstone. A transparent stone appears clearer and deeper and is often more valuable than a cloudy stone.

However, transparency must be assessed differently depending on the gemstone. High transparency is especially valued in aquamarine, sapphire and spinel. In emerald, by contrast, inclusions are very common and are partly accepted as part of the stone’s natural character.

Not necessarily. Inclusions are natural features within a gemstone. They can provide information about its formation and help distinguish natural gemstones from synthetic stones or imitations.

Whether inclusions reduce value depends on the particular stone and its overall appearance. Strong inclusions can impair transparency, stability or beauty. In other gemstones, such as emerald or demantoid, certain inclusions may be characteristic and form part of the stone’s natural character.

“Eye clean” means that no distracting inclusions are visible to the naked eye. The stone appears clear to the eye, even though natural features may be visible under magnification.

For many coloured gemstones, “eye clean” is an important quality term, but it should always be considered together with colour, transparency and cut.

The cut determines how effectively light, colour and brilliance are displayed in a gemstone. A good cut can significantly enhance a stone’s beauty, while an unfavourable cut can weaken its colour, light performance and proportions.

With high-quality coloured gemstones, the aim is not only symmetry, but also to bring out the best possible colour, depth and light performance from the rough stone.

The finished gemstone shows only the result. Yet its development begins much earlier - with the selection of the rough stone. Even in its rough state, colour, transparency, inclusions, shape, possible cutting orientation and weight loss must be carefully assessed.

A good cut does not mean retaining as much weight as possible, but finding the best balance of colour, brilliance, proportion and character. This is why the journey from rough stone to cut gemstone is an important part of its story.

Carat is the unit of weight used for gemstones. One carat equals 0.2 grams.

Because gemstones have different densities, two stones with the same carat weight can appear different in size. For this reason, the dimensions of the stone are also important in addition to its weight.

Gemstones have different density values. A sapphire, aquamarine and opal can appear different in size despite having the same carat weight.

The cut also influences the visible size. A shallow stone looks larger when viewed from above but has less depth. A deeply cut stone, by contrast, appears smaller from above.

Two gemstones of the same type can have completely different qualities. A sapphire may be pale, heavily treated or poorly cut - or intensely blue, untreated, transparent and superbly crafted.

The gemstone type alone therefore says little about value. What matters is always the interaction of quality, colour, origin, treatment, cut and documentation.

Pleochroism means that a gemstone can display different colours depending on the viewing direction. Iolite, tanzanite and certain tourmalines are especially well known for this effect.

Pleochroism is important when cutting because the cutter must orient the stone so that its most beautiful colour is displayed to best advantage.

Colour change means that a gemstone displays a distinctly different colour depending on the light source. The best-known example is alexandrite, which may appear greenish in daylight and reddish to purplish under warm artificial light.

A strong and clearly defined colour change is rare and can significantly increase a stone’s value.

A cat’s-eye gemstone displays a narrow, moving band of light across the surface of the stone. This effect is called chatoyancy and is caused by fine, parallel-oriented inclusions.

Chrysoberyl cat’s eye is especially prized when the light band is sharp, centred and clearly visible.

Origin can mean two things: the natural origin of a gemstone as a product of nature, or its geographical origin from a particular country or deposit.

Geographical origin can influence the market value of some gemstones, such as ruby, sapphire, emerald or alexandrite. Nevertheless, the country of origin alone does not determine quality. An exceptional stone from a lesser-known deposit can be more beautiful and valuable than an average stone from a famous region.

No. Renowned sources can influence market value, but they do not replace a quality assessment.

Colour, transparency, cut, treatment, rarity and overall appearance remain decisive. A well-known origin is particularly relevant when the quality of the individual stone is also convincing and the origin is reliably documented.

An untreated gemstone has not been altered by gemmological processes. These include, for example, heating, oiling, filling, dyeing, irradiation, stabilisation or coating.

Untreated gemstones are especially sought after when they also possess beautiful colour, good transparency and attractive quality. However, a stone is not automatically valuable simply because it is untreated. The decisive factor is always the combination of beauty, quality, rarity and documentation.

That depends on the type and extent of the treatment. Many treatments are well known in the gemstone trade and are widespread for certain stones. What matters is that they are disclosed transparently.

A minor, clearly documented treatment may be acceptable for some gemstones. Extensive or undisclosed treatments, by contrast, can significantly affect value. We therefore place great importance on clear information and traceable documentation.

Emeralds often contain natural inclusions and fine growth features. For this reason, many emeralds are treated with oil or other fillers to improve their appearance.

For valuation, it is important to know what type of treatment is present and how extensive it is. For example, one distinguishes between no, minor, moderate or significant oiling or filling. An emerald with fine green colour, good transparency and only minor, clearly documented treatment can be of very high quality. The main concerns are extensive, unstable or undisclosed treatments.

A certificate or laboratory report can provide important information about a gemstone, such as its gemstone type, natural origin, treatment and, in some cases, geographical origin.

Reliable documentation is particularly important for valuable gemstones such as ruby, sapphire, emerald, alexandrite, Paraíba tourmaline or padparadscha sapphire. It creates confidence and facilitates professional assessment.

Not every smaller or moderately priced gemstone necessarily requires a comprehensive laboratory certificate. However, a certificate is highly recommended for particularly valuable, rare or collector-relevant stones.

The decisive factor is the relationship between value, rarity and the cost of testing. For high-quality individual stones, a certificate from a recognised laboratory can significantly strengthen both value and traceability.

A gemstone passport documents important information about a stone, such as gemstone type, weight, dimensions, cut, colour, origin information, treatment disclosures and other characteristics.

It does not replace an independent laboratory certificate, but it can provide valuable documentation for an individual gemstone - especially when origin, selection and processing are presented transparently and traceably.

A natural gemstone formed in the Earth and was subsequently cut and polished.

A synthetic gemstone was created in a laboratory but essentially has the same chemical composition and crystal structure as its natural counterpart.

An imitation merely resembles a gemstone but is made from a different material - for example glass, plastic or another mineral. 

Natural gemstones are not industrially manufactured. They form over millions of years under particular geological conditions. Every stone is unique: colour, inclusions, structure and light performance differ from one specimen to another.

It is precisely this individuality that makes natural gemstones so fascinating. They are not standardised products, but unique pieces created by nature.

Padparadscha refers to a rare sapphire colour between pink, orange and salmon. Harmonious, natural shades with good transparency are particularly sought after.

Because the precise colour boundaries are not always clear, reliable laboratory reports are especially important for padparadscha sapphires.

Paraíba tourmaline refers to copper-bearing tourmalines with vivid neon colours in blue, turquoise or greenish blue. The name originally derives from discoveries in Brazil, but today it is also used for copper-bearing tourmalines from other origins that display a similar colour appearance.

Important factors include neon colour, confirmation of copper content, transparency, origin and reliable documentation.

Natural zircon is a genuine gemstone that formed in the Earth. It has strong brilliance and occurs in various colours, including blue, honey, champagne, brown, green and colourless.

Cubic zirconia, by contrast, is a synthetic material frequently used as a diamond imitation. Zircon and cubic zirconia should therefore not be confused.

Natural gemstones can be of interest to value-conscious collectors and as long-term tangible assets. However, they are not standardised financial products. Their future value cannot be guaranteed and depends on quality, rarity, demand, documentation and market conditions.

Exceptional, rare and well-documented coloured gemstones with fine colour, good transparency, natural origin and ideally no treatment, or only transparently documented treatment, are especially relevant. These include, above all, high-quality rubies, sapphires, emeralds, alexandrites, spinels, Paraíba tourmalines, tsavorites, demantoids and padparadscha sapphires.

Rare coloured gemstones of exceptional quality are particularly relevant. These include ruby, sapphire, emerald, alexandrite, Paraíba tourmaline, spinel, tsavorite, demantoid, padparadscha sapphire and high-quality jadeite.

Special varieties such as mandarin garnet, rubellite, indicolite, chrome tourmaline, imperial topaz or fine opals can also be of interest to collectors when quality and rarity are convincing.

A jewellery gemstone is valued primarily for its beauty, colour and wearability. It should work well in a piece of jewellery and suit the person wearing it.

A collector’s gemstone is additionally assessed according to rarity, quality, origin, treatment, documentation and particular gemmological significance. Some stones can be both: beautiful jewellery gemstones and, at the same time, of interest to collectors.

No. A trend can increase demand, but it does not replace a quality assessment. Some trend gemstones are primarily sought after in jewellery design, while others also have collector potential.

The individual specimen always remains decisive: colour, transparency, cut, rarity, treatment, origin and documentation.

At present, colourful, individual and rare gemstones are particularly sought after. These include spinel, Paraíba tourmaline, padparadscha sapphire, mandarin garnet, tsavorite, demantoid, rubellite, indicolite, chrome tourmaline, fancy-colour sapphires, teal sapphire, parti sapphire, aquamarine, morganite, tanzanite, opal, natural zircon and iolite.

Design stones such as malachite, lapis lazuli, turquoise, moonstone and labradorite are also popular in jewellery, but they are generally associated less with traditional value considerations than with colour, style and expression.

Rarity can have various causes. A gemstone may be geologically rare, occur in only a few deposits, be difficult to find in good quality or be exceptionally rare in larger sizes.

However, not every rare stone is automatically valuable. Rarity must be combined with beauty, demand, quality and documentation for a gemstone to be significant in terms of value.

It is not only the choice of gemstone type that matters, but also the colour, transparency, cut, size, treatment, origin, rarity and documentation of the individual gemstone.

A good gemstone should not only be objectively high in quality, but also appeal on an emotional level. It should possess colour, light and character - and suit the person for whom it is intended.

Natural gemstones are personal and lasting gifts. They are unique, durable and rich in symbolism. No two stones are alike, and it is precisely this that creates a special connection.

Whether as a jewellery gemstone, keepsake or collector’s stone, a natural gemstone can preserve a moment, a relationship or a phase of life in a special way.

Durable gemstones with good hardness and stability are particularly suitable for everyday jewellery. These include ruby, sapphire, spinel, chrysoberyl, many garnets, aquamarine and tourmalines.

More sensitive stones such as opal, kunzite, moonstone, turquoise, malachite, chrysocolla, titanite or apatite should be worn more carefully. They are better suited to protective settings, pendants, earrings or jewellery that is not exposed to heavy daily wear.

More sensitive stones are primarily those with lower hardness, cleavage, porosity or sensitivity to heat, light or chemicals. Examples include opal, turquoise, malachite, chrysocolla, kunzite, moonstone, titanite and apatite.

These stones can be exceptionally beautiful, but they require greater care when worn, cleaned and stored.

Many gemstones can be cleaned carefully with lukewarm water, a soft cloth and, if necessary, a small amount of mild soap. They should then be dried thoroughly.

Aggressive cleaning agents, intense heat, chemicals, hard brushes and prolonged direct sunlight should be avoided. Particularly sensitive or treated gemstones such as emerald, opal, turquoise, malachite, kunzite, moonstone or chrysocolla require especially gentle care.

Caution is required with many gemstones. Ultrasonic cleaners can damage sensitive, treated, porous, fractured or heavily included stones.

Emerald, opal, turquoise, malachite, moonstone, kunzite, chrysocolla, pearl and many treated stones should generally not be cleaned in an ultrasonic cleaner. Even with hard gemstones such as ruby or sapphire, ultrasonic cleaning is only safe when the stone is untreated, stable and securely set. When in doubt, gentle cleaning by hand is always the better choice.

Gemstones should be stored separately so that harder stones do not scratch softer ones. Soft fabric pouches, padded compartments or jewellery boxes with separate sections are ideal.

Sensitive stones should be protected from strong sunlight, heat, chemicals and moisture.