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There are no fixed prices for gemstones. Besides many important criteria, supply and demand, but also fashion trends influence the price. Their value is as difficult to determine as that of jewellery or works of art.

Gemstones can be purchased through many different procurement methods. Whether directly and personally at a gemstone wholesaler, during a sales trip or trade fair. An order can also be placed conveniently by telephone, in writing via e-mail or with just a few clicks in an online shop for gemstones.

No matter which purchasing method you choose, you should always pay attention to a number of tips when buying gemstones. Especially when buying online, there are other important points that you should know and take to heart. Find out more at the end of this blog!

Overview: What to look for when buying gemstones? 

- Detailed shopping description
- Choose the right gemstone dealer
- The 4 C's (carat / colour / cut / clarity)
- Colour nuances of a gemstone
- Appraisal of the gemstone before purchase
- Independent certificate
- Inexpensive and high quality gemstones
- Synthetic gemstones
- Treatment methods
- Place of origin and mine


1. Describe as best as possible which gemstone you would like to buy 

You are looking for a special gemstone, are bound to the specifications and wishes of your customer and only have a corresponding budget? To make it easier for the seller, it is important to give as many details as possible to the gemstone dealer so that he can check whether he has a gemstone in the right class available. Information regarding some of the following points is helpful:

Gemstone type | Price range | Size | Carat | Purity | Colour | Cut | Treatment


2. Be careful when choosing a dealer

Buying gemstones is a matter of trust. Check what information the gemstone dealer provides. Only buy where transparent and trustworthy information is provided regarding origin, production and ethical conditions and, if applicable, where the expert advice and sympathy are right after a personal meeting.

3. Know and observe the 4 C's

Since beauty is in the eye of the beholder and therefore cannot be used as an objective criterion for determining the value of a gemstone, other quality characteristics are needed to determine the quality of a stone.
In order to be able to determine the value of a gemstone, gemstone experts such as gemstone cutters, dealers, gemologists or institutes are usually required. They check the stones according to the following quality characteristics:

- Carat - What is the weight of the stone?
- Colour - How intense and special is the colour?
- Cut - What cut does the stone have? What is the optical play of light?
- Clarity - How many inclusions does the stone have? How pure is it?

When determining the value of diamonds, all four quality characteristics are weighted equally. With gemstones and coloured diamonds, the finest differences and nuances have a decisive impact on pricing. For example, in the case of coloured gemstones, the colour as a criterion determines up to 50 percent of the value of a specimen. But clarity and cut also have a high weighting. With carats, the monetary value usually increases exponentially for the same quality.

Besides the 4 C's, there are other factors that affect the determination of quality and value, such as occurrence and rarity, as well as origin and current demand.


4. Colour nuances of a gemstone type

As also included in the 4 C's, the colour is an important indication of the high quality of a stone. The colour is a criterion that is obvious. Usually, a certain shade of colour is considered particularly valuable for a type of gemstone - you should know these popular colour nuances. If you want to buy an aquamarine, for example, a deep blue sea blue "Santa Maria colour" is usually more valuable than a light light blue.

In our blog posts about a particular type of gemstone, you will always find information about the colour variations of the stone and which of them are the most popular. In our article "Tourmaline - The most colourful gemstoneParaiba tourmaline with its intensely bright turquoise-blue colour is of such high quality that it is purchased as a valuable investment.


5. Examining the gemstone before buying it

Before you decide to buy a gemstone, hold the stone up to the light. Look closely at the stone, if possible with a magnifying glass, and examine it for unwanted irregularities in the colour, look at the refraction of light and, if necessary, the colour gradient. Also check the stone for inclusions and purity and of course for its cut - are the facets cleanly struck, do they run precisely towards each other?

Visit us at our company headquarters in Kirschweiler (Rhineland-Palatinate, DE). Get a presentation of our gemstone collection, a guided tour of the traditional HC Arnoldi cutting workshop and take a close look at our specimens. Or take advantage of our offer to have a selection of gemstones sent to you free of charge so that you can find the right gemstone and view it at your leisure beforehand.

6. An independent certificate

In the case of high-quality and multi-carat gemstones, an independent certificate issued by an internationally recognised gemstone laboratory, such as the German Gemmological Institute (DGemG) in Idar-Oberstein, can be requested. This serves as proof of the correctness of the information regarding treatment, natural purity and high quality. Often the gemstone cutters or gemstone dealers take care of this. Just ask your partner about it!

On request and from a certain value of the gemstone, a certificate checked by the DGemG can be requested via HC Arnoldi also offers the issuing of house certificates. Feel free to contact us for this!

7. Inexpensive and high-quality gemstone types

The type of gemstone alone can have a corresponding effect on the price. This mainly concerns the occurrence - does the gemstone exist in high or low quantities on the market? The rarer a gemstone, the higher its price.

High-quality gemstones include: 
aquamarine, tourmaline, spinel, mandarin, garnet, sapphire and tanzanite.

The inexpensive ones include:
amethyst, citrine and topaz.

In our online shop we offer high priced as well as low priced gemstones. With we would like to offer start-up entrepreneurs, small goldsmiths but also established jewellery manufacturers and other companies the possibility to purchase calibrated goods, unique specimens and gemstones in the range of 5 Euro to 20,000 Euro per piece.

8. Identify synthetic gemstones

Synthetic gemstones are crystallised, man-made products whose physical and chemical properties largely match those of their gemstone counterparts. Simply put, they are an imitation. Since the counterfeit is very similar to the real gemstones in terms of physical properties, it is usually almost impossible to tell the difference. But how can you tell if it is a synthetic or genuine gemstone?

- If in doubt, have an examination carried out by a gemmological laboratory. With the help of certain instruments, they can determine whether it is an imitation or not.

- Question the price! If it is a so-called "bargain", it is important to question whether it is really a natural gemstone.

- Take a close look at the stone! Look at the refraction and the colour. A few inclusions, for example, can be an indicator that it is a genuine specimen.

- Do the hardness test! Take a mineral with a lower Mohs hardness and rub it firmly against the stone. A genuine diamond, for example, cannot be scratched with any other mineral (this is of course at your own risk).

We at do not offer synthetic gemstones.


9. Treatment methods and their effect on pricing

Many of the gemstones available on the market are treated to optimise their optical properties, especially their colour. As a rule, untreated gemstones are more expensive than treated ones. Learn about different treatment methods and know which treatments increase value and which decrease value.

In our blog post "Gemstone processing methods

10. The origin of the gemstone

The country of origin can be decisive for the price. For certain gemstones, mining locations serve as a quality designation, such as the Santa Maria aquamarine, named after a mine in Brazil. Thus, under certain circumstances, even with lower-quality stones, you pay for the origin.

We have the same with
Paraiba Tourmaline. A Paraiba Tourmaline from Brazil has a much higher value than a Paraiba Tourmaline from Mozambique. However, the Paraiba Tourmaline from Mozambique also has a considerable value.


How to buy gemstones Online

Buying gemstones online is becoming more and more popular because it is quick and easy. However, it is often difficult to judge the quality of gemstones from a distance. Even though gemstone dealers usually offer a right of return, people want to save themselves a bad purchase and not fall for dubious suppliers.

How can I tell if it is a trustworthy gemstone supplier? 
We answer this question in this video, in which Carl-Philip Arnoldi explains what to look out for when buying gemstones online.


Our vision at

The company was founded in the gemstone town of Idar-Oberstein and offers gemstones that have largely been processed here in the region. All gemstones offered here in the online shop undergo a strict quality check. Every single gemstone is examined and evaluated according to our quality standards. In this way, we guarantee a reliable and, as far as possible, consistent quality. Furthermore, only gemstones from conflict-free countries are offered in our online shop.

Learn more about us here!

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