How do you identify good chocolate?

based on the hall mark given by food department of respected country example in india green mark

Of course, tasting it would be a good way to find out. But if you're comparing brands at a shop and can't taste them all, there's an easy way to tell. The one with the highest percentage of cocoa solids will be the best quality. If you can get an organic brand, that'll be of a higher quality too, as the ingredients will be organic, therefore better. If a company cares enough about its product to ensure it uses quality ingredients, and knows enough about real chocolate to keep the cocoa solids high and the cocoa mass low (and not to use artificial crap), it's a fair guess that the quality of the product will be better, and it'll be made with care by experts. Anything with the name "Mars" "Cadbury", "Nestle" or "Hersheys" isn't worth bothering with if you want the real quality. "Cadbury" chocolate is probably the best of the bog-standard brands, but still isn't really serious chocolate. Try "Green & Black's" or "Thornton's" if you can - they're fairly easy to find in the UK, and do have websites - I know Thorntons delivers around the world, and Green & Black's probably does. Those brands are both excellent; reliable and good quality chocolate. Happy eating!