Gneiss doesn't directly "come from" a specific rock type. It's a metamorphic rock, meaning it's formed from existing rocks that have been subjected to intense heat and pressure.

Here's how it works:

* Starting Material: The original rock can be any kind of rock - igneous, sedimentary, or even another metamorphic rock.

* Metamorphism: The original rock undergoes transformation due to intense heat and pressure deep within the Earth's crust.

* Recrystallization: The minerals within the rock recrystallize and align themselves in layers or bands, giving gneiss its distinctive appearance.

So, while you can't say gneiss specifically comes from one type of rock, it can be formed from a wide range of sources. Some common starting materials for gneiss include:

* Shale: This sedimentary rock is a common source for gneiss, especially when metamorphosed under high pressure.

* Granite: This igneous rock can be transformed into gneiss under intense heat and pressure.

* Other metamorphic rocks: Even existing metamorphic rocks like schist or slate can be further metamorphosed into gneiss.

It's important to note that gneiss is a broad category of metamorphic rocks, and the specific rock type it originates from will influence its composition and appearance.