<p>It really depends, first of all you can open only one shell every 20 hours, secondly, after opening the shell you can get one of the three options:</p><ul><li>find a Giant Shimmering Pearl</li><li>find nothing</li><li>squeeze your fingers resulting in a loss of 200 <a rel="nofollow" href="https://tibia.fandom.com/wiki/Hp" title="Hp">hp</a> (equipment href="https://tibia.fandom.com/wiki/Hp">hp</a> (equipment will lower the damage).</li></ul><div>All damage).</li></ul><p>All the options have a similar chance so depending on your luck, I'd say no less than 200 days.</div>days.</p><p>P.S. I would also like to add some statistics that I have found just now:</p><p><img alt="" src="https://i.gyazo.com/296c4dcd356559fc86e80834c5394d91.png" style="height:195px; width:445px"></p><p>It seems that you have more or less 50/50 chance of getting a pearl. This concluded that, as I've mentioned before, you need around 200 attempts (days more or less)</p>