Change item symbol within itemize in beamer

Question

I'm using beamer to create a presentation and I'd like to mix item shapes. Namely, I'd like to use something like

\begin{itemize}
\item[\circle] Something
\item[\triangle] A conclusion
\end{itemize}

What's the name of the triangle shape used as a beamer template?

Answer 1

Adapting the answer here:

• beamer: change individual bullet color in itemize list

\documentclass{beamer}
\useinnertheme{circles}
\newenvironment{trienv}{\only{\setbeamertemplate{items}[triangle]}}{}
\newenvironment{squareenv}{\only{\setbeamertemplate{items}[square]}}{}
\begin{document} 

\begin{frame}
  \frametitle{Some bullet shapes}
    \begin{itemize}
      \item<tri@1-> A triangle item
      \item<square@1-> A square item
      \item A circle  item
    \end{itemize}
\end{frame}

\end{document}