Im trying to find "ritual" tagged spells. Under the tags in the search boxes under all spells, Ritual is not an option. And 2 spells I thought were rituals don't have th tag (Identify and Find familiar). 

Is there a list of ritual spells?

Show advanced filters, there is a specific dropdown for filtering Rituals (yes/no).  Looking for rituals brought me here too!

Casting word is:

Incanticus Determinium

I thought this spell was a bit OP for it's level until I saw the pearl material component. I notice that the text does not say "which is consumed on use" like many spells with high value parts do. I assume that the caster needs this Pearl as opposed to an arcane focus or component pouch ? Any thoughts ?

No, the pearl could not be replaced with an arcane focus or component pouch based on RAW because a cost (100 gp) is specified for the pearl: 

But if a cost is indicated for a component, a character must have that specific component before he or she can cast the spell. Basic Rules: Chapter 10: Spellcasting

Yes I get that, thanks. Could the caster use the same pearl multiple times ? I ask because the text does not imply "consumed on use".

That is correct. The same pearl can be used for infinite castings of the spell. 

Thank you Ecozar.

This spell is dumb y would you have a 100GP pearl at first level

Can you use one pearl between 2 person with the same spell? (share the pearl) 

Quote from Zthulhu >>

This spell is dumb y would you have a 100GP pearl at first level

 

You don't, but your entire party might help you.

Quote from Liveforyou >>

Can you use one pearl between 2 person with the same spell? (share the pearl) 

Yes, it's just an item.

Think an item housing a being (such as Shield of the Hidden Lord) or a sentient item (Sword of Kas) would be able to block/resist identification?

In advanced search theres an option to search for rituals :)

Quote from Lugh_of_the_Long_Hand >>

Think an item housing a being (such as Shield of the Hidden Lord) or a sentient item (Sword of Kas) would be able to block/resist identification?

 As the DM, you can specify that the Identify spell must be cast at a certain spell level (i.e. slot) in order to learn specific things. 

For instance, there's a Magic Sword with +1 to hit and Damage (standard), but also has additional +2 against Kings. The enchanter who created the blade knew that kings of the land wouldn't permit such a weapon, so it would need to be kept secret! Any identify can sense the lower level magic, but only a high-level Identify can detect the secret magic! Obviously a first level magic user can't learn the secrets a 20th level magic user doesn't want him to learn!

Optionally, you can give a hint that there's more to learn after the 1st level Identify. Or else, give the item some property that raises questions. In the example above, if the sword starts vibrating when it gets close to the King, the owner should realize that something is going on.

Does this spell when cast as a ritual only mean you spend 10 minutes casting it to avoid having to use up a spell slot?

Quote from CaileynRothenel >>

Does this spell when cast as a ritual only mean you spend 10 minutes casting it to avoid having to use up a spell slot?

 Correct!

FYI everyone wrt to cursed items (b/c it wrecked a twist at my table); "Most methods of identifying items, including the identify spell, fail to reveal such a curse, although lore might hint at it. A curse should be a surprise to the item’s user when the curse’s effects are revealed."  <-- from the DMG

There's at least one exceptional item in Tales from the Yawning Portal with a curse that DOES get clocked by identify.

Also, you can taste a potion to ID it instead of wasting time on the spell.  In this case the exception is the potion of poison, which will taste like a healing potion... but identify DOES reveal its true nature!

It seems like the juice isn't worth the squeeze with this spell, especially in the first tier, but probably into the second as well. "Handling a magic item is enough to give a character a sense that something is extraordinary about the item. The identify spell is the fastest way to reveal an item’s properties. Alternatively, a character can focus on one magic item during a short rest, while being in physical contact with the item. At the end of the rest, the character learns the item’s properties, as well as how to use them. Potions are an exception; a little taste is enough to tell the taster what the potion does" (Basic Rules for Dungeons and Dragons Ch.14).

Aside from not being tricked by poison, is there a reason to take "Identify," if it can't reliably suss out if an item is cursed or not? (asking for a friend)

Because you could only identify one item per short rest otherwise. You can spend three hours IDing three items your party found, or 33 minutes. When you're mid-dungeon, that can make a massive difference.

Edit to add the minute's casting time, since ritual is 10m + casting time.

Also, identifying and attunement are different acts, so could take two hours to identify and then attune to one item (depending on your interpretation of RAW).

Right, the time. I appreciate your reply, thank you.