the green lace was in a lush cave. almost got lost exploring it but it was adjacent to an amethyst cave. got attacked by two zombies. then going back found three diamonds in part of the cave. that was at level -27. got to stock up on food and torches and go back down..
i think a new chunk develops when you settle there. i moved from spawning point to a new home. there a zombie dropped a carrot and now i have food for pigs. from there i went east and when daylight was almost gone, i dug in and made a bed and slept. then the next day i wanted to explore. within a hundred clicks i found a shipwreck. now how can that be. i think that shipwreck developed because i slept there. very strange to me.