How do I polish stones?

[naive]

Following previous (fantastic) answers I've got on this site... I now have some lovely usable lumps of obsidian, however the cutting process have left the stones dull/scratched looking (as might be expected!) what's the best method for shining it up again (before it had a glassy look to it)

Thanks in advance :)

[spudqueen]

With a stone polisher
http://www.littlegemsrockshop.co.uk/acatalog/s tone_polisher_machines.html

[heathfield]

Almost impossible without the kind of equipment used for polishing semi-precious stones. This comprises a lapidary 'flat lap' machine similar to the ones shown here.
Different grades of carborundum and other grits are used in turn to remove the scratches, each subsequent finer grade grit giving a finer finish. (The final polishing grit will look like talcum powder).
Obsidian comes up very well, but it would be obviously uneconomic to buy the equipment. It might be best to find out if any lapidary club in exists your area and go about contacting them. They're usually only too pleased to help. Alternately, commercial polishing services are available. Look up 'lapidary' in Google.
Good luck!