Types of Opals
SIX Types of Opals here is some easily understandable confusion in nomenclature on the part Tof the public in respect to what constitutes a "type" of opal. The reason for such confusion is that there are a number of adjuncts to the meaning of "type." There arc, for example, types involving color (black opal, light opal, gray opal, etc.}, types involving pattern (harlequin opal, broadflash opal, pinfire opal, etc.), types involving value (black opal, light opal, harlequin opal, etc.), types involv- ing location (Lightning Ridge opal, Virgin Valley opal, Mexican opal, Hungar- ian opal), types involving formation (boulder opal, nobby opal, nut opal, sand- stone opal, seam opal, pipe opal, matrix opal, etc.), types involving clarity (transparent opal, translucent opal, opaque opal, etc.), types involving genesis (volcanic opal, sedimentary opal, vegetable opal), types involving cuts (baroque, calibrated, freeform, etc.), and the list goes on and on with more categories and subcategories. Indicative of the whole problem of what it is we're really talking about in regard to types of opal is the fact that even while basically, there are only two real types of opal—precious opal and common opal—precious opal itself (the opal that is so valuable as a gemstone) is very often erroneously referred to by people as fire opal. Yet true tire opal docs not even have play of color (POC), or, if it docs, then it must properly be called precious tire opal. Then there are many types of precious opal and, equally, many types of common opal. But there are two fundamental types of precious opal, which deal with its genesis— volcanic opal and sedimentary opal—and those headings are themselves further broken down into different types, as are other categories of opals.
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