Chalk
Rock
Take care.
- Fragile: Handle it gently and pack it well; it breaks or crumbles easily.
About it
Soft, white, porous limestone made of microscopic calcite plates from coccolithophores; it marks paper and fizzes in acid. Forms the White Cliffs of Dover and holds flint nodules and Cretaceous fossils.
- Type
- Rock (sedimentary)
- Group
- Sedimentary (biochemical)
- Lustre
- earthy, dull
- Colours
- white, cream, light grey
- Transparency
- opaque
Typical values: real specimens vary. For more, see mindat.org.