G'day Adam,
My advice would come under the heading "General".
Firstly, do not send any top quality "Large" stones overseas. ( here I'm talking "Precious", like Sapphires, rubies, Peridot, natural blue topaz,etc.).You will lose a lot of their value with facets not joining up.
With small faceting stones of lower quality don't send stones that aren't completely transparent. They are of no use when setting and clear small stones are cheap to buy over here at many markets.
With opaque colorful stones for "Cabbing" make sure the ones you send don't have visible cracks in them as polishing the stones will make the cracks more obvious.
With less valuable stones such as Garnets, Zircons, colored Quartz, clear Topaz, etc let them decide the best cut to get the largest stone possible. Larger versions of these stones are more valuable than smaller. If you specify "Calibrated" most of the time they will cut large amounts of valuable facetable material off the stone to calibrate it. Ask them to calibrate only the smaller stones.
We send many hundreds of stones to Lamberts and have been more than happy with the results. We can certainly recommend their services.
Again the most "IMPORTANT" advice i can give is NEVER send a large clear Sapphire or Precious Gem to a general cutting shop either Local or Overseas. Get advice on these from a recognized Jeweler. These stones are graded on the quality of their cut. Faulty cuts can halve their value, and re-cutting can be a costly exercise in more ways than one.
Cheers Wal.
