To quote a part of your addition It is si o4 silicon dioxide and water water is an important part of opal as only in recent times it was discovered what makes the colour in precious opal that islight passing thru microsopic voids between water molecules Surely you can see the lazy typing errors in that You slap something together and expect someone else to fix it for you In addition it is totally unreferenced with just acouple of ext links One of those links is a gem dealer site basic info but not reliable as it is a commercial site The Mindat link is OK but only says that it is a variety of opal A Google search returns lots ofcommercial sites hyping the stuff but virtually no legitimate refs Sorry bout that