Sorry to wreck this train but I have used LRs configured temporarily at 1G speed while we wait for the distant end to be upgraded and capable of 10g:
SSH@0XXX-RTR-G1#sh media | inc 1/2/2
Port 1/2/2: Type : 10GE LR 10km ((SFP+))
SSH@0XXX-RTR-G1#sh int br | inc 1/2/2
1/2/2 Up Forward Full 1G None No 1 0 609c.9fb4.8ab8