Program aims to educate young consumers about mined stones’ positive qualities.
Project will see company move underground at several pits and attempt underwater mining.
Extra year could add 2.2 million carats of rough production.
Production up 43% year on year following mine takeover.
Miner unearthed stone weighing 71.26 carats.
Revenue and profit from Rio Tinto’s diamond division soared in the first half of the year as demand strengthened and manufacturers replenished inventory.