“stone” in Japanese is 石, read seki, shaku, ishi (せき, しゃく, いし). It is a Grade 1 Kyōiku kanji, taught in year 1 of Japanese elementary school, and appears in words such as 石ころ (pebble).
What does 石 mean?
石が大きい。
Same sound, different character — the classic trap. Compare them side by side: