Sacred metal fragments are items dropped in the Battle of Lumbridge world event. They are obtainable by killing NPC soldiers of the enemy faction and are dropped in quantities of 1 to 20 or by performing skilling actions while silver nodes are present. An Icyenic greathammer head, orb, or bowstaff, or Infernal greathammer head, orb, or bowstaff can be used with 1,000 of these fragments to complete the respective weapon override. Having the drops or overrides has no bearing on whether or not you can receive fragments. In the behind the scenes video on the 31st of August, it was announced that the chance of these fragments to spawn in the place of divine tears would be increased. During the final few days of the event, there was one mining node right outside of the Saradomin camp that stayed metal permanently.
A pool of divine tears temporarily affected to give fragments
A rock of divine tears temporarily affected to give fragments
A formation of divine tears temporarily affected to give fragments
Until the seventh week of the battle, starting Monday 2 September2013, only up to a maximum of 10 sacred metal fragments were dropped or received from skilling at a time.
After a system update, which first introduced Bonds, there was a glitch where one of the divine tear rocks (closest to the Saradomin camp) was active in the form of a sacred metal rock for an indefinite period of time. This meant that players could acquire an unlimited supply of sacred metal fragments as well as mining experience. An in-game update was soon applied to fix this glitch. However, it was discovered and confirmed by numerous Mods that this was in fact not a glitch, but an intentional feature which was originally released too early. So on 30 September, this indefinite rock was intentionally brought back as a final treat.
The addition of an inexhaustible sacred metal rock in the last two days of the battle provided players with an excellent source of mining experience. As a result, dozens of players at any given time mined away at the rock, each of them being left with many thousands of sacred metal fragments--more than they could have ever needed to complete the six available weapon overrides.