Ozone Gas can only be found in aerial environments. It is almost undetectable, being invisible to all but the finest of optics. Because it is highly oxidizing, the presence of ozone can be inferred because of the damage and hue shift present when inside the cloud.
Gathering ozone is simply a matter of sitting inside ozone clouds and harvesting it, but because of the damage it causes, this can be risky.
You must have the highest level of Optics MK-8 to detect the Ozone Cloud areas , or you can also use Radar Pulse to detect the Ozone Cloud area. The Mithril Ore is especially useful when harvesting Ozone Gases . When your probe is at full upgrade, the Ozone Cloud environment will damage your probe by 2 full unit of health. One unit of Mithril Ore can repair the same amount of health damaged. So store some Mithril Ore with you when you go harvest the Ozone Gases in the Ozone Cloud.
Can be found at:Edit
Aerial Planet: 150-250 altitude
Ozone Gas can be obtained by holding your machine in ozone cloud. When inside the Ozone cloud, the game will take on a yellow tint.Here is an ozone cloud: