Ersatz shards are artificially created Khaydarin crystals. After losing Aiur, the Protoss were left with few resources to rebuild their empire. To compensate for the lack of traditional and sacred crystal mines, they turned to the Dark Templar for advice on how they developed technology on their world. Through these teachings, the Protoss psionically forged the shards to replenish their military and civilian forces (Star Wars: Synth-crystal).