You can use the Lodge 26.04 cm Cast Iron Skillet on a glass cooktop, but you need to take some precautions to avoid damaging the surface. Here are the key points to consider:

- Clean and Dry Bottom: Ensure the bottom of the pan is clean and dry before placing it on the glass cooktop.
- Avoid Sliding: Lift and gently place the cookware on the stove instead of sliding it, which can cause scratches.
- Risk of Cracking: Be careful when setting the pan down to avoid cracks and damage to the glass.

By following these guidelines, you can safely use your cast iron skillet on a glass cooktop.