Does the alembic root file shows in the hierarchy, or are there any errors when importing the file?
Is it possible for you to send me the .abc file support@paradoxnotion.com to check it out?
Regarding materials, once the file is imported, it’s meshes will show in the Unity hierarchy panel. Materials can then be assigned as normal to those meshes.
Please let me know on the import process and the file send if possible.
Thanks.