\begin{itemize}
\item Marble is a metamorphic rock formed from limestone or dolostone.
\item Sandstone is a sedimentary rock formed from sand-sized mineral particles or rock fragments.
\item Quartzite is a metamorphic rock formed from sandstone.
\item Slate is a metamorphic rock formed from shale or mudstone.
\end{itemize}
Therefore, Sandstone is NOT a metamorphic rock.