Meaning
The kanji 岩 means rock or boulder — not any pebble, but the large, ancient, immovable masses of stone that define dramatic landscapes. Think of a rugged coastal cliff, a volcanic mountain range, or the rocky face of a hiking trail: that's the world of 岩.
Visually, 岩 is easy to decode. 山 (mountain) sits on top and 石 (stone) on the bottom. A mountain made of stone — that's the image, and that's the meaning. When you see 岩, think: solid rock, all the way down.
Etymologically, 岩 is an ideograph (会意文字, kaii moji) — a kanji formed by joining two meaningful components to create a new concept. Mountain + Stone = Rock. If you already know 山 and 石 — among the first kanji taught in Japanese schools — 岩 clicks into place immediately.
岩 has 8 strokes — 山 contributes 3, 石 contributes 5. It's taught in Grade 2 of Japanese elementary school, yet keeps reappearing through N2 and beyond, in geological, geographical, and literary contexts. Its radical is 山, placing it in the family of kanji tied to elevated, rugged terrain. Volcanic activity, hot spring descriptions, landscape poetry — 岩 shows up across all of them.
Readings
On'yomi (音読み) — Chinese-derived readings
ガン (GAN) is the on'yomi. Borrowed from ancient Chinese, it appears almost exclusively in compound words (熟語, jukugo), especially in formal, academic, and scientific contexts. Geologists, geographers, and nature writers use ガン when naming rock types, geological phenomena, or terrain features.
岩石 (ganseki) — rock, stone (the standard geological term for any solid mineral mass)
溶岩 (yōgan) — lava (literally "melted rock"; essential vocabulary for discussing volcanoes)
岩盤 (ganban) — bedrock (the solid rock layer beneath soil; used in construction and geology)
岩塩 (gan'en) — rock salt (mineral salt extracted from underground deposits)
花崗岩 (kakōgan) — granite (one of the most common rock types in the Earth's crust)
Kun'yomi (訓読み) — Native Japanese readings
いわ (iwa) is the kun'yomi — the native Japanese word for a large rock or boulder. This is the reading you'll encounter most often in casual speech, literature, and place names. いわ carries a weight and permanence that suits poetry and nature writing. Japan's rocky coastlines and volcanic terrain have produced a rich vocabulary built around this word.
岩 (iwa) — rock, boulder (the most direct way to say "rock" in Japanese)
岩山 (iwayama) — rocky mountain, craggy peak (a mountain dominated by exposed rock)
岩場 (iwaba) — rocky terrain, rock face (used widely in rock climbing and outdoor contexts)
岩陰 (iwakage) — shelter behind a rock, the shadow cast by a boulder
岩棚 (iwadana) — rock ledge, a natural horizontal shelf of stone on a cliff face
Common Words & Compounds
岩 forms compounds across geology, nature, architecture, and everyday life. The examples below are grouped by theme.
Geological & Scientific Terms:
岩石 (ganseki) — rock, stone (the umbrella geological term)
溶岩 (yōgan) — lava (magma that has reached the surface)
岩盤 (ganban) — bedrock (the solid foundation beneath soil and sediment)
岩塩 (gan'en) — rock salt (naturally occurring mineral salt)
花崗岩 (kakōgan) — granite
石灰岩 (sekkaigan) — limestone
玄武岩 (genbugan) — basalt (dark volcanic rock)
Nature & Geography:
岩山 (iwayama) — rocky mountain, craggy peak
岩場 (iwaba) — rocky terrain (especially used in climbing)
岩礁 (ganshō) — reef, submerged rocks in the ocean
岩壁 (ganpeki) — rock wall, sheer cliff face
岩窟 (gankutsu) — rocky cave, cavern carved into stone
Everyday & Cultural:
岩風呂 (iwaburo) — rock bath (a hot spring tub built from natural stone; a signature feature of Japanese ryokan)
岩陰 (iwakage) — shelter behind a rock, shade of a boulder
岩棚 (iwadana) — rock ledge, natural stone shelf
Example Sentences
大きな岩が道をふさいでいた。
Ōkina iwa ga michi wo fusaide ita.
A large rock was blocking the road.
子供たちは岩の上に座って海を眺めた。
Kodomotachi wa iwa no ue ni suwatte umi wo nagameta.
The children sat on a rock and gazed at the sea.
火山から溶岩が流れ出た。
Kazan kara yōgan ga nagare deta.
Lava flowed out from the volcano.
この地域の地盤は岩盤でできているので丈夫だ。
Kono chiiki no jiban wa ganban de dekite iru node jōbu da.
The ground in this area is sturdy because it's made of bedrock.
登山者は険しい岩場を慎重に登った。
Tozansha wa kewashii iwaba wo shinchō ni nobotta.
The climber carefully scaled the steep rocky terrain.
温泉旅館の岩風呂がとても気持ちよかった。
Onsen ryokan no iwaburo ga totemo kimochi yokatta.
The stone bath at the hot spring inn felt absolutely wonderful.
岩石の種類を調べるのが彼の趣味だ。
Ganseki no shurui wo shiraberu no ga kare no shumi da.
Researching different types of rocks is his hobby.
嵐の後、船が岩礁に乗り上げてしまった。
Arashi no ato, fune ga ganshō ni noriagete shimatta.
After the storm, the ship ran aground on a reef.
古代の人々は岩に絵を刻んで記録を残した。
Kodai no hitobito wa iwa ni e wo kizande kiroku wo nokoshita.
Ancient people carved pictures into rocks and left behind records.
Memory Tip
Picture standing at the top of a mountain (山), looking down at massive stones (石) beneath your feet. The mountain is built from stone — and that's exactly what the kanji shows: 山 on top, 石 on the bottom. Next time you spot a dramatic boulder on a hike, picture those two components stacked together and 岩 will stick.