The method
Behind every figure there is a criterion with a name
ValorGem does not invent prices: it structures the methodology and reference base of a practicing gemologist so any jeweler can issue appraisals that are coherent, traceable and verifiable.
Who is behind it
Alfredo G. Notario
Gemologist
Specialist in the analysis of cut and rough gems. ValorGem's price base and valuation criteria are the result of decades of field work and teaching — the same table he uses to value real pieces, now structured as a tool.
- 40 years teaching groups of jewelers across several provinces of Spain
- Author of the Commercial Gemology and Diamond Certification with a Reticle Loupe courses
- Appraiser of rough and cut diamonds in the field in Africa (Sierra Leone, Democratic Republic of the Congo, Zimbabwe, Guinea-Conakry and Senegal)
- Buying and valuation experience in the Antwerp and Tel Aviv diamond bourses
- Author of the books «Las gemas en su interior» and «Las gemas bajo la Lupa 10x»
- Creator and holder of the patent for the 10x-loupe system that distinguishes synthetic from natural diamond (Hikari Synthex Lens)
- Creator of the Gemología y Ciencia outreach project
ValorGem’s methodology and reference base are those of Alfredo G. Notario, gemologist. Each report is issued and signed by the jeweler or appraiser who writes it, under their own name and establishment: the method is the starting point, not a third-party certification.
How a figure is built
A price base curated by a gemologist
Over 18,000 price references for 110 gem and diamond types, organized by quality, treatment, intensity and weight range. Not internet scraping: it is the working table of a practicing appraiser, corrected and expanded piece by piece.
Value depends on what it is appraised for
The same jewel is not worth the same for an inheritance, insurance, resale or auction. Every report declares its valuation basis and applies the matching factor, so the figure is defensible in its context.
Technical adjustments, not guesses
Strong fluorescence in a diamond, treatments and their intensity, synthetic versus natural: the factors that move price are encoded with gemological criteria, and the appraiser always has the final word on the figure.
Quality you can compare by eye
Over 900 reference photographs by quality, so grading a stone as "Fine" or "Commercial" does not rely on memory: you compare your stone with real examples of each step of the scale.
What if the piece falls outside the table?
For singular pieces you can book a consultation with the team of gemologists — identification, valuation and authentication with an answer in under 2 hours.