Sort categories into order, check for missing categories, and insert blank row for them

I have a grave problem with a data set and they looks like this.

Jewel A
Jewel B
Jewel C
Jewel F

Jewel A
Jewel C
Jewel K
Jewel G
Jewel F

Jewel F
Jewel K

Steps need to perform:
1. I need to sort them out in order. For each of the above groups, sort them into order, i.e. Jewel A-Z.
2. Search for missing categories, e.g. in group 1, Jewel D and Jewel E, and Jewel G-Z is missing.
3. Insert a blank row for each of the missing values.

I have googled all day and found something similar without using VBA (http://www.oleksiygayda.com/2011/03/...=1368608500584), but ran into a problem with that solution as I always end up deleting the rows with useful information.

Any help would be greatly appreciated!