It would be best to do this in surat as it is the cheapest place in the world for polishing. Israel is 2nd.
Sorry I've changed my username a few times, since I've lost my password. I'm an older member as such. Also (I just lost my login again after clearing private data on my browser so now have a newbie id again).
The issue about trust could be managed using escrow etc better if we have a Texan on board too (i.e. a citizen of Texas, that is where the facility of the US lies. i.e. the one I have experience with.)
I agree trying hpht processing in surat may be a risk. I'll test it using a small batch, the people of Gujarat are highly enterprising and would have probably figured out how to use them machines by now.
I have not been doing this continuously for 2 years, I did it 2 years back and then as I was working on a cloud based collaboration environment for teams(a different startup)I didn't have time to continue doing what would get me good profit regularly and went to do a startup that had a technical element to it (maybe so it'd justify my engg degree) which was a risky dot com dream.
Also last time I did this I invested 6 BTC it is better to have a higher investment as sending 3 carats of diamonds and sending 30 carats of diamonds cost the same only the customs duty is proportional to the amount of diamonds sent but still pretty cheap in India like Israel which too tries to keep the diamond trade environment conducive for business.
You could google and learn about all that I've said. Also I feel things would be much more professional if the investment is made legal...not social contract legal a serious contract valid in indian and international court of law. There is room to have 49% international investment and control for a business run in India.
Also if there are people who'd like to become trading partners in their own countries, It's be good to have regular buyers who use Crypto. Although is not vital for running the business.
A lot of good questions have been asked. It's best to make an educated decision so plz let me know if you need any other clarification.
It might be nice to start the exchange now but it being a new avenue might require me to do better R&R/research.
Also without the diamond stock backing the exchange's currency it does not have a Unique Selling Point which I feel should really push the exchange in a good light.
Go to the below mentioned link.
Pledge an amount for now It'll help us understand how many investors would it require.
https://www.ethercalc.org/ojibxajbgyMore about hpht color enhancement:
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&sqi=2&ved=0CC4QFjAC&url=http%3A%2F%2Fwww.hphtdiamonds.com%2Ffaq.html&ei=as4-VJaQMNiRuASuyID4Bw&usg=AFQjCNFzy-2gb-aJd2BHl8n56BtZOva2QA&sig2=KwnjDlWI8VnJmI6_5K1Yyg