Travertine
Rock
Also called Onyx marble and Mexican onyx
About it
Dense, banded calcite rock with small holes, laid down by hot or cold springs and in caves; it fizzes in acid. Mammoth Hot Springs in Yellowstone and Pamukkale in Turkey build it today; the Colosseum in Rome is built of it.
- Type
- Rock (sedimentary)
- Group
- Sedimentary (chemical)
- Hardness (Mohs)
- 3–4
- Lustre
- dull
- Colours
- cream, tan, white, gold, brown, banded
- Transparency
- opaque
Typical values: real specimens vary. For more, see mindat.org.