Your Adventurer's Tome in Lost Ark contains a collectible item called Sand in a Bottle. You can only find the collectible on the Arthentine Continent, where it appears randomly every so often.
Where is the Sand in a Bottle in Arthentine?
Larger monsters tend to drop Sand in a Bottle more often. You can increase your chances of finding the Sand in a Bottle by going straight for the special monsters.
You can earn collection items in a variety of ways. Since monsters drop them randomly, it really comes down to luck and good old-fashioned farming. Sand in a bottle is like a snowglobe, but with sand. It has a base, and it looks like the desert is inside.
If you intend to include it in an adventurer's book, then you should take it to a secluded, safe location. Origins of Stern is usually the best option since it doesn't have any enemies.
Open your Inventory by pressing the I key and then right-click on Sand in a Bottle. The Adventurer's Tome will notify you when the Sand in a Bottle Collection is added.