The facts
What trilobite actually is
Mineralogically, trilobite is fossil arthropod exoskeleton, Cambrian to Permian, preserved in limestone, shale or as a calcite replacement — Calcite CaCO3 after an originally calcitic cuticle; pyritised examples occur, crystallising in the aggregate system.
The colour is caused by matrix and replacement mineralogy. That is worth knowing because it determines what heating, light and time can and cannot do to the stone.
A refractometer reads 1.486-1.658, and the specific gravity sits near 2.6-2.9; cleavage is none in the fossil itself.
Where trilobite comes from
The recognised sources are Alnif, Jbel Oufatene and the Draa Valley, Morocco (Devonian), Wheeler and Marjum Formations, Millard County, Utah, USA (Cambrian), Jince, Czech Republic; Dudley, England (historic) and St Petersburg region, Russia (Ordovician, exceptional preparation).
Origin affects price in this material, so we name the locality on every quote rather than the country. "African" or "Asian" tells a buyer nothing.
How trilobite is treated
The Moroccan trilobite trade is notorious for outright fakes carved from stone and cast in resin, and for composites glued from several animals with sculpted spines - assume any spectacular cheap Moroccan Psychopyge, Walliserops or Dicranurus is enhanced until proven otherwise. Russian and Utah material is generally honestly prepared. Export from Morocco needs permits under the 2015 Mining Code that are usually absent; export from China is prohibited outright. Not CITES.
None of this is a problem when it is said out loud. It becomes one the moment it is left out.
What trilobite is confused with
The usual confusions are Carved stone and cast resin fakes, Composite specimens and Repaired and repainted specimens.
The separation is rarely a matter of opinion: refractive index 1.486-1.658 and specific gravity 2.6-2.9 settle most of it in a minute, and magnification settles the rest.
What trilobite is used for
Trilobite is bought by mineral collecting and decorative objects — and each of those trades wants a different form of the same material.
We quote each application in the unit that trade actually buys in, by the specimen or by the piece.
Durability and care
Trilobite is 3-4 on the Mohs scale, with none in the fossil itself cleavage.
Below about 5.5 a stone will be scratched by ordinary household dust, which is largely quartz. That does not make it unusable — it makes it a pendant, an earring or an object rather than a ring worn every day.
Warm water, mild soap and a soft brush. Avoid ultrasonic cleaners on anything fracture-filled, stabilised, dyed or visibly included.
What trilobite costs
Indicative pricing for trilobite is $15-150 for ordinary prepared Moroccan and Utah specimens; fine Russian and rare spiny species $500-30,000.
That is a range, not a quote. Colour, size, clarity, cut and origin move the figure a long way inside it, and the only honest price is one given against a specific stone. Send us what you need and we will price it.
Questions
Is trilobite treated, and how?
The Moroccan trilobite trade is notorious for outright fakes carved from stone and cast in resin, and for composites glued from several animals with sculpted spines - assume any spectacular cheap Moroccan Psychopyge, Walliserops or Dicranurus is enhanced until proven otherwise. Russian and Utah material is generally honestly prepared. Export from Morocco needs permits under the 2015 Mining Code that are usually absent; export from China is prohibited outright. Not CITES.
Where does trilobite come from?
Alnif, Jbel Oufatene and the Draa Valley, Morocco (Devonian), Wheeler and Marjum Formations, Millard County, Utah, USA (Cambrian), Jince, Czech Republic; Dudley, England (historic) and St Petersburg region, Russia (Ordovician, exceptional preparation). Origin affects price, so we name the locality rather than the country on every quote.
Is trilobite hard enough to wear every day?
Not really. At 3-4 on the Mohs scale it is softer than the quartz dust in ordinary household dirt, so it scratches with wear. It suits pendants, earrings and objects better than a daily ring.
How much does trilobite cost?
Indicatively $15-150 for ordinary prepared Moroccan and Utah specimens; fine Russian and rare spiny species $500-30,000. Colour, size, clarity and origin move the price a long way within that, so treat it as a range and ask for a quote against a specific stone.
What is trilobite confused with?
Most often Carved stone and cast resin fakes, Composite specimens and Repaired and repainted specimens. A refractive index of 1.486-1.658 and a specific gravity near 2.6-2.9 separate it quickly.
Related stones
Looking for trilobite?
Tell us the size, the quality and what it is for. We source it, photograph it and quote it — with the locality named.
Ask about trilobite