Graptolite
Fossil
About it
Colonial animals preserved as thin, saw-edged lines like pencil marks on dark shale; the name means rock writing. Abundant in Ordovician and Silurian shales of Britain, Australia, and North America, and used to date them.
- Type
- Fossil (other)
- Group
- Graptolite (hemichordate)
- Colours
- black, silver-grey, white, on dark shale
- Transparency
- opaque
- Periods
- Ordovician, Silurian
Typical values: real specimens vary. For more, see mindat.org.