Indian Agate is from the Chalcedony group of stones defined by their microcrystalline structure.  Agate is generally translucent to semi-transparent and Indian Agate comes in a range of colours and colour combinations, including green, pink, orange yellow and red, with green being the most common colour.  This particular carving has irregular patches and mottled banded markings on a two tone base colour of yellow brown and green brown, with an orange and black mottled band dividing the two colours. 

Agate is a grounding stone, said to be particularly useful in deep meditative practice to assist with self confidence and one's stability in the world; that is having a deeper understanding of one's place and value, irrespective of the goings on with other people.  Agate can be metaphorically akin to your supporting foundation stone in this respect.

More specifically to Indian Agate and the particular colouring of this stone, one can take this further in deep meditative practice to add a greater level of strength and a sense of security to considerations of your self confidence, and support healing of past trauma that has caused self confidence problems.  The beautiful and relatively uncommon colouring of this stone, considering the size, can also bring you good luck. 

Stone carved into the human skull form is a tool that can be used with meditative practice to expand your consciousness.