01Decisive
It scratches glass
Dyed jasper is quartz at hardness 7 and will scratch a glass plate; lapis at 5–6 will not do so cleanly. This is the reverse of the usual direction and easy to miss.
Lapis Lazuli · Lovenhall Stone
How to Identify Dyed Jasper ('Swiss Lapis')
An old and still-current substitute: pale jasper dyed deep blue, with no pyrite at all.
Badakhshan, Afghanistan — the same mines for six thousand years — with Chile and Siberia
Dyed jasper has been sold as lapis under the trade names Swiss lapis and German lapis since the nineteenth century, which is long enough that the names have a certain currency in the antique trade. The material is fine-grained quartz — jasper or chalcedony — dyed with an iron or synthetic blue.
It gives itself away in two ways. There is no pyrite, because dye cannot produce metallic inclusions, so the material is a flat even blue with none of lapis's gold speckling. And it is hardness 7, harder than genuine lapis, so it will scratch glass where lapis is more reluctant.
Under a loupe the dye shows the usual signature: concentrated colour along grain boundaries and in any fracture, with a slightly mottled distribution that follows the rock's texture rather than a mineral's composition.
Model-specific checks
What decides a Dyed Jasper ('Swiss Lapis')
These apply to this model and not to the rest of Lapis Lazuli. Work them alongside the maker's general checks, not instead of them.
02Strong
No pyrite at all
Dye cannot make metallic flecks. A completely even blue with no gold speckling anywhere is suspicious on its own, since lapis without pyrite is uncommon and expensive.
The market
What a Dyed Jasper ('Swiss Lapis') does on the secondary market
Cheap. Honest as dyed jasper; a misrepresentation as lapis.
An orientation for honest, unrestored condition — never an appraisal, and never a quotation.
All the Lapis Lazuli checks
Free tools of the room
Lovenhall StoneRead the stone itself
The tests tell you what it is. The instrument reads a photograph and offers a name to start from — then hands you back to the tile and the coin, which are what settle it.
Free on iPhone & iPad. An estimate, never an appraisal.
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