Subject: English 'mass' unit, Metric 'weight' unit?

In my chemistry class we learned that mass is a measure of the "amount of 
matter" in a substance and that weight equals the mass of an object multiplied 
by the acceleration due to gravity.  Thus, the mass of an object is constant 
but the weight of an object is variable.  In the English system weight is used 
and in the metric system mass is used.  However, I have never seen an English 
unit for mass.  Conversely, I have never seen a metric unit for weight.  Do 
such units exist?  If so, what are they called?

Re: English 'mass' unit, Metric 'weight' unit?