Harriet Kelsall's reply:
The Gem-A courses are really good and if you contact them I’m sure they would be able to help you answer your question about different entry routes into gemmological careers. Give them a call - they are very nice and are likely to know if any apprenticeships exist too. They are at www.gem-a.com.
You could look into the NAG courses (for valuation and appraisals more than gemstones in particular) but they are mainly aimed at retail too I think but I might be wrong.
You could look into lapidary work (ie cutting gemstones) and you might be lucky enough to find an apprenticeship in this kind of area perhaps if you contact a few companies perhaps in London or Birmingham in particular.
If I were you also try just contact stone cutting and diamond grading companies and offer yourself for a weeks unpaid work experience, work hard and make yourself really useful and see where it leads. You could try this a few times perhaps to have a bit of a look round the industry that way.