Julius Ngwa (asker) Jul 6, 2016:

The company quarries stones, some of which is used for cement production.

Nikki Scott-Despaigne Jul 6, 2016:

Without more context, it is difficult to think how this might be intended. Might it not simply translate as "rich stones"? Difficult to suggest much more without context in the form of an extract from the original containing the phrase you have provided.

B D Finch Jul 6, 2016:

Context? What minerals are being quarried? What is the client's business?