Velocities required to move a mineral packet from the Moon to Earth are much lower than those involved in our usual meteors encounters, so it could be quite feasible to just drop the thing and expect good survivability of such a packet. For comparision purposes, Earth moves around it's orbit at 30km/s, not counting planetoids' own orbital velocity, while as sneaky pete mentioned, 3km/s should be enough of a "nudge" for lunar mining purposes.
(no maths whatsoever performed. Just a general intuition)
Anyway, let me remind you - the only really valuable thing on the Moon, which can't be accessed cheaply on Earth is He3. It accumulated for millenia(or more accurately, since the Moon got it's surface solidified and tidally locked, whichever came first) on it's far side, where the bulk of it's mass acted as a shield for Earth's magnetic field, which has a healthy ability of deflecting ionized particles from solar wind, such as abovementioned helium isotope. Now, today He3 is very expensive to extract on Earth, but the demand is also very small, however, should the ongoing projects aiming at building commercially viable fusion reactor succeed, then it'd become a really valuable commodity indeed.