Stone polishing required for broken semi precious stone

Hi!
I dropped a pendant and broke it in 2 pieces. I’ve been told is a semi precious stone from New Zealand.

Is anyone able to polish the 2 pieces?
Is there any way to determine the shape on polishing?
I’m not sure if it’s possible to drill a hole in the second smaller piece so I can make that into another necklace?
See image below:

I look forward to hearing from you!
Many thanks in advance for any advice and cost!

Warmest wishes,
Christina