Here is a good formula for a beautiful strong concrete countertop:

4 parts white cement

1/4 fly ash

4 white sand

4 marble dust

1/3 fiber

It creates a nice white counter top that is also very strong. We do custom concrete counters and find that this formula really works. We sometimes add decorative aggregate. One that really works is broken up salvaged glass from discarded tempered windows. The tempered glass breaks up into nice little pellets. You can really pile it in there to the point where there is almost more glass than anything else. It gives a nice effect.

custom made concrete countertop installer

Here is a counter that we colored with a little blue. It was for a bathroom counter installation

Another similar formula we like:

1 part cement (30% fly ash, 70% white cement)

2 part sand/dust (50% white sand, 50% marble dust)

2 parts glass pellets

1/4 water (50% concrete glue, 50% H2O)

This has a slightly coarser look, although it feels the same since you sand it down with super fine marble sanding.