An artifact that gave a plus six to Occult would be power level three and it would be more effective than that lab, as it would be able to effect more than just Alchemy. Â That would be just a power level two because it just effects a specialty of Occult. Â Considering that it is also bulky, fragile and probably requires maintenance, it would be a level two artifact.
Mortal usable artifacts are artifacts that have been made so efficiently that they do not require anything more than ambient Essence or artifacts with Essence Storage Crystals. Â In general, to reduce the mote cost to 'mortal usuable' levels, add ten successes per mote of operating cost to the artifacts. Â Essence Storage Crystals are treated as an extra power. Â A 20 Essence crystal is power 1, a 40 Essence is power 2, etc. Â Either one requires significant investment of time, which is why it is usually only done with low level artifacts, like shock pikes.