Harry’s summoning circle question

[ntribley]

In his lab, Harry mentions his copper summoning circle. Hadn’t he upgraded it to silver in a prior book? With the Svartelves having done the work?

[Mira]

In his lab, Harry mentions his copper summoning circle. Hadn’t he upgraded it to silver in a prior book? With the Svartelves having done the work?

  I remember him talking about the upgrade with the addition of the silver ring, however I don't remember him mentioning who did the work.

[Lazarus52980]

If I remember correctly, that was in Changes before it all burned down.  I just assumed it was lost when that happened.

[tarontwo]

It was braided, silver, iron and copper if I remember right he comments on it being expensive to get them to work with iron.