The Cryptic era is an informal term for the earliest geologic evolution of the Earth and Moon.
It is the oldest (informal) era of the Hadean eon, and it is commonly accepted to have begun close to about 4.533 billion years ago when the Earth and Moon formed, and lasted to about 4.15 billion years ago.
[1] Neither this time period, nor any other Hadean subdivision, has been officially recognized by the International Commission on Stratigraphy.
Most geological landforms and rocks were probably destroyed in the early bombardment phase, or by the continued effects of plate tectonics.
The Earth accreted, its interior differentiated and its molten surface solidified during the Cryptic era.