- Phyllosilicate macdonaldite was discovered near the Sierra Nevada foothills, California.
- Macdonaldite appears as Tulare counties in California.
- Macdonaldite crystallises in the orthorhombic system.
- Macdonaldite is anisotropic with low relief.
- The Macdonald seamount ( 5, 600 km south of Hawaii ) and the mineral macdonaldite ( IMA 1964-010 ) were named in his honour.