This is an ingredient for making a “Brown Diamond of Earthâ€, which is used to make a “Ceramic Totem of the Ratheâ€. This Totem has an Improved Heal IV focus effect, that why your cleric wants it. https://everquest.allakhazam.com/db/item.html?item=17859
Just to clear it up. Clerics no longer use Dots for buffs. So don't let them fool you. Enchanters however, got shanked and still use Dots for Rune spell line.
Well, clerics do have a spell that uses these, but its the spell to summon a yellow diamond of valor, which consumes one of these, and a metallic liquid.
But as far as claiming gems, thats usually a cleric who either wants to recoup peridot costs, if its the first gem to drop, or if they ask for all of them, is playing you.
The yellow diamond of valor sells for about 5-7k on my server, and is used in the valorium ring of gallantry, and possibly other recipes (ceramic shield of valor?).
I priced this at 190pp from a vendor. My cha is huge; can't remember offhand; and amiable faction. Obviously not sure what you'd get, but it probably beats that 150pp in the post header.
Used to combine with Alkaline etched stone to form White Diamond of Justice (Shaman imbue justice spell), which is then combined with 2 crystalized cloudy eyes to form Glittering Ring of Judgement (10ac 20wis 50hp). All components found in PoJ.
These are used for the Planar Imbue spells (along with an appropriate liquid drop) to create [color]Diamond of [plane]. These are then used in Tradeskillds typically.
eg. Imbue Nightmare (Nec/Enc) Summons Black Diamond of Nightmares requires Raw Diamond and Nightmare Mephit Blood as reagents.
Also can be used in the recipe Greasy Gem of Innovation (see EQ Traders forums).