Eisenstein integers

The Eisenstein integers, sometimes also called the Eisenstein-Jacobi integers, are numbers of the form a+bomega, where a and b are normal integers,
omegacongruent1/2(-1+isqrt(3))
is one of the roots of z^3 = 1, the others being 1 and
omega^2 = 1/2(-1-isqrt(3)).
The sums, differences, and products of Eisenstein integers is another Eisenstein integer.
Eisenstein integers are complex numbers that are members of the imaginary quadratic field Q(sqrt(-3)), which is precisely the ring Z[omega]. 

The field of Eisenstein integers has the six units (or roots of unity), namely ±1, ±omega, and ±omega^2.