I'm sorry
KenJackson:, that you haven't had more help with this question so far. But like
Corribus: said, you're really not being clear. I suspect the problem is just as much with this particular Wikipedia definition. Let's try to break apart your question,and see if our Physical Chemistry masters can help us -- because I'm out of my depth here.
From Wikipedia: Ringwoodite is a high-pressure phase of Mg2SiO4 formed at high temperatures and pressures ...
OK. That's simple enough. I can follow that much.
Ringwoodite is notable for being able to contain hydroxide ions (oxygen and hydrogen atoms bound together) within its structure.
OK. Wikipedia says that's notable. But is that really notable? Sodium hydroxide is a solid, it has -OH groups within its structure. Copper Sulfate pentahydrate has water molecules in its crystal structure. We call carbohydrates that just because when we heat them,water comes off, leaving carbon, sugars exist as molecules with -OH groups as well.
Maybe this Wikipedia statement says nothing at all. Kids edit Wikipedia, and many feel like giving a "high school term paper" definition is awesome. Or maybe this is a poor translation from another language.
I want to know if I am correct that releasing water from soaked crystals is endothermic.
Annnd, that is a possibility, or it may not be the case. But you may not be able to say anything from the quotes you have.
I guess there's two steps--releasing the OH ions, and then converting them to water and oxygen.
And, that's not how we release water from the examples I gave above.
I don't know how to begin.
Well,you've made up some chemistry above, and also in your second posting, but we can still get to the answer you need. But there will need to be some more baby steps of knowledge to get ready. But we're here to help.