How to complete the interesting items?

So, top row, left to right:
- Air can be collected by dropping a villager on the small tornado that occasionally forms on the northwest beach, near the fire.
- Steam can be made by combining air and water in the crafting hut (takes 10 min), or by dropping a villager in the water where the lava flows in, near the love shack.
- Worm can be made by combining fertilizer and bacteria in the crafting hut (takes 8 hrs), or may be found randomly in the cracks that sometimes appear on the island.*
- Butterfly can be made by combining worm and strawberry in the crafting hut (takes 24 hrs)
The rest of the items are found randomly in cracks that sometimes appear on the island.*

* Early in the game, you will get an event where you can choose to pull a totem out of the ground, or push it in. Pull it out, and from then on there will be random earthquakes that open cracks, which your villagers can explore for random prizes, including crafting items, quest items, "interesting" items, or a random amount of tech points. In order to explore the cracks, your villagers need rope, which can be made in the crafting hut from two vines (takes 5 min). Vines can be found in four locations around the island: two to the northwest, one near the cave, and one near the waterfall stairs. If you have $10 to spare, you can purchase the lemur to climb into cracks for your villagers so you don't need to make rope anymore.

I have been getting the jewels from sending villagers down the cracks. You can combine vine with vine to make rope. It only takes 5 mins for each rope and there are 4 places to gather vines so it's easy to spend a day gathering and crafting rope so you always have some on hand.