[texhax] Bold symbols

[John Podesta]

   I am using T1 font encoding, i.e.,
\usepackage{T1}{fontenc}
\usepackage{mathptmx}

and I need a bold \xi.  The usual command is $\boldsymbol\xi$. (LaTeX)
However, this is not working with the T1 font encoding.  How can
I access these bold symbols?  Thank you very much for your help.

John Podesta
Courant Institute of Mathematical Sciences
New York University