How to Write 钴 (gǔ) — Meaning “cobalt”

Imagine a 'metal' (钅) 'drum' (古 sounds like 'drum' in English) made of cobalt. The drum is a bright blue color like cobalt blue, so you remember 钴 is a metal that makes blue pigments.

The left side 钅 has three horizontal strokes; the lowest stroke turns upward into a hook. The right side 古 has a horizontal stroke on top, then a vertical stroke with a small horizontal at the bottom; make sure the vertical stroke goes straight down without slanting left. A common mistake is writing the right side too wide — keep it narrow to balance the left radical.

钴 (gǔ) is cobalt, 钍 (tǔ) is thorium, and 钎 (qiān) is a drill rod. Visually, 钴 has 古 on the right, 钍 has 土 (earth), and 钎 has 干 (dry). All share the metal radical, but the right parts differ in meaning and pronunciation: 钍 uses 'earth' because thorium is a soil-related element, while 钎 relates to a tool.

钴 appears mainly in science and industry, for example in 钴元素 (the element cobalt) and 钴蓝 (cobalt blue, a pigment used in ceramics and paints). It is not a common daily character, so learners encounter it mostly in chemistry or art contexts.

Common words containing 钴 include: 钴蓝 (gǔ lán) — cobalt blue; 钴元素 (gǔ yuán sù) — the element cobalt; 金属钴 (jīn shǔ gǔ) — Cobalt metal.