This is what's left in a shovelful of earth at the end of the 3-riddle process, the bigger stones, glass shards and perennial weeds having already been extracted by riddles #1 & #2. So, that's about a tea cupful in a shovelful.
My dilemma now is whether to bother with the hand riddling, which removes this last cupful. I'm wondering if there's any point, and indeed if this amount of gravel could actually benefit the soil.
Gravel helps with drainage, which is a serious point in its favour. It helps break up heavy clay - and I do have some of that in the diggings from drainage works.
There's an immediately pragmatic issue here. I need to get the really nasty glass out of the soil asap, so that the dogs can come back to the plot; (the little bits of glass you can see in the photo are unlikely to do any harm ). And, I would like to get it ready for planting by spring, of course. #3 riddling is by far the most time-consuming and laborious part of the process.
Voila. Decision made. I'm going to put the hand riddle aside.
And I'm starting no-dig this year, throughout. But that's another blog post.