A Type C plug in Luxembourg?
Yes — it seats, though without a guaranteed earth.
Luxembourg's Type F and Type C sockets accept a Type C plug (Europlug). The plug is unearthed by design, so nothing is lost in translation. The wall delivers 230 V at 50 Hz (207–253 V within tolerance) — if your device isn't rated for that (look for "100–240 V" on the brick), an adapter won't save it.
Grid facts verified against IEC World Plugs — Luxembourg. Physical-fit verdicts derive from pin geometry and each socket standard's acceptance list — not safety advice.