Judging quality
Look for the cell structure to run continuously across the whole face, tight cells rather than crumbly ones, and saturated color. Fractured or stabilised material is common and should be disclosed.
Fossil
Agatised Dinosaur Bone
Jurassic sauropod bone in which the marrow cells have been replaced cell by cell with agate and jasper — 'gembone'. The best Utah material shows red and yellow cells outlined in black, holding a mirror polish.
Care
Hard and stable, like agate. Water and a soft cloth.
History & lore
US federal land rules distinguish sharply between casual collection of petrified wood and vertebrate fossils; reputable gembone comes from private or state land with documentation.
Cultural history, recorded as tradition rather than as medical or scientific claim.
Common questions about Agatised Dinosaur Bone
- What is Agatised Dinosaur Bone?
- Jurassic sauropod bone in which the marrow cells have been replaced cell by cell with agate and jasper — 'gembone'. The best Utah material shows red and yellow cells outlined in black, holding a mirror polish.
- How hard is Agatised Dinosaur Bone and what is it made of?
- Agatised Dinosaur Bone is a Fossil-family mineral with the composition SiO2 replacing bone. It crystallizes in the trigonal system and rates 6.5-7 on the Mohs hardness scale. It occurs in red, yellow, brown, black.
- Where does Agatised Dinosaur Bone come from?
- Notable localities for Agatised Dinosaur Bone include Colorado Plateau, USA (Morrison Formation), Utah, USA, Wyoming, USA.
- How do you tell good Agatised Dinosaur Bone from filler?
- Look for the cell structure to run continuously across the whole face, tight cells rather than crumbly ones, and saturated color. Fractured or stabilised material is common and should be disclosed.
- How do you care for Agatised Dinosaur Bone?
- Hard and stable, like agate. Water and a soft cloth.
See it in person
Photographs only go so far
Both rooms are open six days a week, and there is always someone happy to pull pieces out of the case so you can compare them under the light.