one sound, two letters
matteucia, with one c
Two c's, for the same reason there are two t's.
one sound, two letters
Both doubled pairs come out of the surname and neither survives an English pronunciation. The tt at least sits between two vowels where a careful speaker might give it some weight. The cc has no chance: it falls in the unstressed run at the end of the word, where English flattens everything. If you can remember that the name is Matteucci with an a added, both pairs come back at once.
The class
A doubled letter said once, so the ear counts one and the page needs two.
Same name
Other spellings recorded for matteuccia
The name