Diomond business

I have been giving a lot of thought to the diamond business, especially in my state(KASHMIR) where I think there is a huge gap for diamond ornaments. Neither a dedicated store for diamond nor someone is doing online regionally. I have been taking interest in the topic. I have also been researching the lab grown diamonds.

I need to better understand the business, about the margins, cost and everything. What amount should I keep in mind while setting up the business. Some one from similar lines of business, kindly drop some advice.