Dura, SCP 409, immune.

Log of event 682-E18: Dr. █████ attempts to use SCP-409 on SCP-682. General ███, General ██████, and Dr. ██████████ observing.

0400: Exposure. SCP-682 began to tear at the point of contact, causing massive trauma to the area. SCP-682 requests several times to know what it has been exposed to.

0800: Crystallization begins, spreading much slower than normal.

1200: SCP-682 shows signs of extreme pain, and begins having seizures

1300: Crystallization stops at 62% conversion. Crystallized area explodes, causing massive physical trauma to SCP-682

1400: SCP-682 recovers from exposure, despite the loss of limbs and organs. SCP-682 begins regeneration, stating that it will attempt to kill and consume all staff involved in Event 682-E18.

SCP-682 appears to now be immune to SCP-409. Use of other SCP items to terminate SCP-682 must now first be tested on samples of SCP-682 before full-scale testing.