Well kind of....
The oil that Marzocchi puts in your fork at the factory is Golden Spectro 125/150 Cartridge Fork Fluid. It is a Synthetic/Petroleum blended product. I've used other stuff in my Zocch forks, but have yet to find anything that performs better. The nice thing about GS is that it can be purchased at motorcycle shops for about $8.50 to $10.00 a quart. That is a significant savings over the smaller bottles of (the same) stuff that Marzocchi sells with their name on it. And depending on the fork, you can get at least 2 oil changes out of a quart, sometimes 3. Anyway thats the stuff that comes from the factory and what I would recommend. There are others out there that will work, Silkolene, Motorex, etc. But I haven't found anything that works better than the GS, and there are a few that don't preform as well.
Good Dirt