Is there a word that describes the separation of dollars and cents?

Solution 1:

In general terms, the radix point separates the integer part of a number from its fractional part. In base 10, the radix point is more commonly called the decimal point.

Solution 2:

I'd call that the "decimal point" and it would apply to any number, not just currency values. In other words the "decimal point" is the separator between whole units and decimal fractions of that unit.

Solution 3:

The widely accepted term is decimal separator.

The internationally recognized nomenclature and technical descriptions of currencies, are codified in the International Organization for Standardization (ISO) standard ISO_4217.