Double-struck Capital H
Part of Math Symbols
Double-struck Capital H has no standard Windows Alt code. Copy the character directly, or use its HTML entity or Unicode value instead.
- Alt code
- None
- HTML entity
- ℍ
- Unicode
- U+210D
About this symbol
ℍ stands for the quaternions, an extension of the complex numbers discovered by the Irish mathematician William Rowan Hamilton in 1843, which is why the letter is H. He was so excited that he carved the key formula, i² = j² = k² = ijk = −1, into the stone of Broome Bridge in Dublin; a plaque marks the spot today.
Unicode facts
- Official name
- DOUBLE-STRUCK CAPITAL H
- Type
- Uppercase letter
- Unicode block
- Letterlike Symbols
- Added in
- Unicode 1.1 (1993)
Click the symbol or any value at the top of the page to copy it. See the full Math Symbols chart for related characters.