Glass-top stoves are more sensitive to contacts with pans than traditional electric coil or gas burner stoves. Since their surfaces are perfectly flat, only pans with absolutely flat bottoms properly conduct heat. Hard anodized cookware normally falls into this category.
Hard Anodized Cookware
This type of cookware is made of aluminum that has been chemically treated and cured with electricity to give it a hard, nearly impenetrable surface. It is heavy and usually has flat bottoms, which make good contact with glass cook top burners. The pans may occasionally create a metal mark on the glass, which should be removed immediately to prevent permanently scarring the surface.
To check if cookware is appropriate for use on glass-top ranges, place enough water in a pan to coat the bottom. Place the pan over high heat and watch the bubbles form. If they form evenly across the surface, the pan is making good contact and will cook foods evenly.
Since hard anodized cookware is heavy, precautions should be taken when placing it on glass stove tops to avoid cracking or breaking the surface. Lift the cookware off the stove top rather than dragging it to prevent unsightly scratches.