I had been climbing about a year, trad climbed a handfull of times and I was off to Wadi Rum, Jordan, with more experienced friends, for a week of multipitch (few hundred meter) trad climbing. The "rock" there is sandstone and has the properties of anything from concrete to sand, mostly something in between though. You place gear in Jordan, but don't fall on it. Rap anchors are either a pair of (big) bonded bolts or slings around sand(stone) pillars. It's quite the experience really.
On the drive up I remember one of my buddies saying "It's pretty easy to know when you're off route there, everything starts to crumble )"...
We were heading up an easier route, on the first day, I don't remember the grade, in a party of three.
I was leading the third pitch, feeling fairly good. The climb was fairly vertical, with big holds. I got to a steep section, of a couple of meters, which had a hand size crack in the beginning of it and looked much harder then the grade afterwards. I placed a bomber tricam in the crack (orange) and looked to the sides for an easier way. It looked worst on my left and there was a groove that looked like it might go about five meters to my right. I made a test attempt up, decided that it was well above the stated grade of the pitch and started traversing to my right. I approached the groove on some pretty big (fridge sized) blocks, reaching the groove. Putting my hand in the groove caused a good ammount of sand to pour down, it was the walls of the groove disintegrating. I threw a big cam in there knowing well that it would not even slow me down, my tricam 5m off to the side. Above me there was a big, vertical, sandstone bridge, 5 inches in diameter with an 8 inch through hole in the rock, all of it protruding out of the cliff face, like an arch. I did not trust it, obviously, so I decided to test it by slowly transfering weight onto it, with one hand, while my feet are firmly on the huge block I'm standing on and my other hand on some other hold.
As I started to load it, the big block I was standing on droped out from under my feet! I hung on the delicat arch, on one hand, for a split second (although every split second seemed like an eternity at the time), seeing the block getting smaller, heading toward the ground, 75+ meters below. My right hand immediately joined my left, on the arch, as I kept looking down to see my feet dangling in mid-air, and the block make its way to the ground and disappear into a cloud of sand a few meters in diameter. I quickly found new footholds on the face and squeezed myself, back first into the sandy groove, breathing hard, my eyes fixed on the delicate arch. A yell of "You should yell rock when you pull something down!" quickly followed, my partners were belaying from an alcove, and could not see me the whole pitch. They then yelled "Is everything ok?" I replied "Yes, I'll just take a couple of minutes to rest.."
I pulled my sandy cam out, traversed back to the tricam, made the sequence above it, which was way harder then the rating of the pitch but on decent looking rock, and made my way up to the next belay.
When my first friend came up, she had a very impressed look on her face, saying she can't believe I had just pulled those moves on lead, they were way harder then the grade. My second friend came up and said that on the left, around the corner, was a section that looked like the grade, and was a bit unhappy he had to pull the moves I did to clean the pro )
I do not like to take un-necesary uncalculated risks, but I have been a big fan of trad since I took those first few steps