Do the guides replace a test?

No. They help to understand, but the proposal is determined only after a physical test.

Are there prices in the guides?

Not fixed ones. A live reference price appears in the gold calculator.

Knowledge center: old gold, silver, casting, and printing

Sell old gold

How to calculate pure gold, what is the difference between 14 and 18 karat, what to do with broken jewelry, and how the purchase price is determined. These guides help understand an estimate and compare offers with confidence.

Testing and verification

A hallmark is just a start. In the guide on testing real gold and the guide on 925 silver, it is explained what can be checked at home, and what only a professional test can determine.

Jewelry manufacturing

What is the difference between a printed model, a cast item, and a finished piece of jewelry, and how gold casting works. Suitable for private customers, designers, and jewelers.

Who the guides are for

For those who found an old jewellery box and do not know what is in it, for those who received an offer and want to understand it, and for those planning a piece of jewellery who want to speak the same language as the jeweller. Each guide stands on its own, but they are structured so that you can navigate between them as needed.

If you want to start from the basics, the guide for calculating old gold value followed by the guide on setting the purchase price provide the complete picture.

How to use the guides

Every guide ends with links to relevant tools — gold calculator, metal calculator, or quote request. Any price shown on the site is a non-binding estimate.

01How to calculate the value of old gold: the formula, examples, and pitfallsThe full calculation formula for the value of old gold: net weight, purity, pure gold, and reference price, with examples and without invented prices.02Price per gram of 14K gold: how to derive it from the market priceHow to derive a reference price per gram of 14K gold from the global gold price, and why the price per gram you receive in a sale is different from it.03How to know if gold is real? What to check at home and what is only professionalWhat can be checked at home (hallmark, magnet, signs of wear) and what only a professional test determines regarding gold purity.04Selling 14K or 18K? Here is how the karat affects the value.Practical comparison between selling 14K and 18K gold: gold content, calculation examples, and considerations for testing.05Where to sell old jewelry? The questions that will help you chooseQuestions to ask every gold buyer, red flags, and comparison between types of buyers — without empty promises or pressure.06Broken gold jewelry: why it is still worth money, and how to sell itBroken chain, single earring, or cracked ring: how to evaluate broken gold, whether to repair before selling, and what to collect.07How the purchase price of old gold is determinedWhat makes up the payment for old gold: reference price, purity, net weight, and general deductions — and why there is a gap from the theoretical value.08How to evaluate the value of 925 silverHow to evaluate sterling silver items: hallmarks, plating vs. solid silver, deductions, and metal calculator.09Gold casting for jewelry: the process, the weight, and the costLost wax casting, metal weight vs. labor cost, and what to check in a model before casting in gold.10Printing, casting, or finished jewelry: what exactly are you orderingThree different stages in jewelry production: printed model, cast item, and finished jewelry. What you get at each stage and what it costs.

Jewellery 3D Knowledge Center