I don't believe the company is going to 8 k every time they have a sale...especialy not for 20 grams. A larger order for KGs with a named customer maybe. . all in good time :)
Selling a few grams of QDs is not a material event but in my opinion, is an event in ordinary course of business. QMC is in the business of making and selling QDs. From SEC website: http://www.sec.gov/investor/pubs/readan8k.pdf
A few thousand dollars in revenue for QMC will just be reported in the next quarterly report, but sign a big or long term deal (millions) and that is material to investors so should end up in an 8-K.