Since we expect top or right lighting to be better, these six images show the effect of more minor adjustments within those ranges. In fact, the difference made by very minor adjustments can be greater than expected. The ease of previewing this is why I prefer to use continuous lights rather than flash.
These six are not exactly evenly spaced and the yellow arrows only approximate the direction. The coin, a silver tetradrachm of Side, has a number of surface problems and scratches which show more strongly in some light angles than in others. I prefer the example in the lower left corner (roughly 1 o'clock angle) for this coin but every coin is an individual and the best results will be found by turning the coin until you see what you want.
These images vary (intentionally) only in the light direction. Other changes could be made by raising or lowering the light (a single CFL bulb) or changing the reflectors used with that bulb. Unfortunately there is accidental variation introduced by the fact that this ancient coin has a reverse that makes it hard to sit perfectly and consistently flat as would be possible with a modern coin with flat relief and raised rims. Also the imperfect alignment of the camera to the coin becomes obvious when comparing the various images. These differences do not become troublesome until you try to shoot matching images.