Judging quality
Look for domed or columnar lamination that stacks upward rather than the flat parallel banding of ordinary sediment. Silicified Bolivian material is harder and takes a better polish than calcareous stock.
Fossil
Stromatolite
Layered structures built by cyanobacterial mats — the oldest evidence of life on earth, with examples running back 3.5 billion years. The wavy laminations polish into striking banded slabs.
Care
Calcareous specimens are acid-sensitive; silicified ones are not. Water and a cloth.
History & lore
Living stromatolites still grow in Shark Bay, Western Australia, in water too saline for the grazers that eliminated them everywhere else.
Cultural history, recorded as tradition rather than as medical or scientific claim.
Common questions about Stromatolite
- What is Stromatolite?
- Layered structures built by cyanobacterial mats — the oldest evidence of life on earth, with examples running back 3.5 billion years. The wavy laminations polish into striking banded slabs.
- How hard is Stromatolite and what is it made of?
- Stromatolite is a Fossil-family mineral with the composition CaCO3 / SiO2 laminae. It crystallizes in the — system and rates 3-7 on the Mohs hardness scale. It occurs in banded, grey, brown, cream.
- Where does Stromatolite come from?
- Notable localities for Stromatolite include Western Australia, Bolivia, Morocco, Wyoming, USA.
- How do you tell good Stromatolite from filler?
- Look for domed or columnar lamination that stacks upward rather than the flat parallel banding of ordinary sediment. Silicified Bolivian material is harder and takes a better polish than calcareous stock.
- How do you care for Stromatolite?
- Calcareous specimens are acid-sensitive; silicified ones are not. Water and a 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.