The names of his children are as follows:
- EkveeraEkveera
- UrmilaUrmila
- LokeshLokesh
- NikhilNikhil
- OmarOmar
- ApekshaApeksha
- IshitaIshita
- MandeepMandeep
- TriptiTripti
- RohitRohit
The gemstone he found is:
Edit: TourmalineTourmaline, solved via anagram of the first initial of each child after solving the correct names. Credit to Billyb for helping.
His name is:
MacDonald, because old MacDonald had a farmold MacDonald had a farm.
Edit: Also Also because the missing vowels are ordered EIEIO.