Amongst all the hammered silver coins that are found by detectorists those of Elizabeth I are amongst the most common. However, when specimens are in reasonably good condition it is worth having them checked out.
Here is a coin of Elizabeth I, which was unearthed by Colin Barton. On the obverse the legend reads E D G ROSA SINE SPINA and on the reverse it reads CIVI TAS LON DON. The mint mark on both sides is a castle and the date over the shield on the reverse is clearly 1570. Colin said the coin measures 15mm in diameter so it must be a threehalfpence piece.
Lots of sixpences, threepences and halfgroats of Elizabeth I have been found by detectorists but the three-halfpence turns up far less regularly. This specimen is a bit weak in places but overall it would grade good Fine for the issue. It has another important factor in its favour: 1570 is a very rare date for this denomination. In its present condition a specialist collector of coins of Elizabeth I should be willing to pay £80 – £100 for it.