There are:

• 150 shards in Neon
• 125 shards in Warren
• 75 shards in Historic

There are a total of 350 of them scattered around the map, and this count does not include shards obtained in other ways (such as from missions, as you noted).

There are:

• 147 shards in Neon ( only 146 reachable till you get a later power )
• 135 shards in Warren
• 68 shards in Historic

There are a total of 350 of them scattered around the map, and this count does not include shards obtained in other ways (such as from missions, as you noted).