This achievement is pretty self explanatory. You will find shards around the map and can get this achievement early in the game from the first 1-3 areas from loot areas or cleansing sites. The ones that are laying around the map you can see using your vision, they will glow yellow when you see them.
NOTE: For anyone who plays coop in case the video above does not mention it. When one player picks up any shard it picks it up automatically for the other player as well.
If Player 2 has already picked up a shard in their own game they cannot see the shard in Player 1's game since they already acquired them.