X'inhuma l-Australian fenomeni ottiċi?

Fenomeni ottiċi ta 'ħaġar prezzjuż

Gemstones fenomeni ottiċi jirriżulta mill-mod kif id-dawl jinteraġixxi ma 'l-istruttura kristallina ta' gemstone. Din l-interazzjoni jew interferenza tista 'tkun fil-forma ta' tifrix tad-dawl, riflessjoni, rifrazzjoni, diffrazzjoni, assorbiment jew trażmissjoni.

Adularità

Adularescence is a blue sheen phenomenon reflecting on the domed cabochon surface of Moonstone. The phenomenon of shimmer comes from the interaction of light with layer of little “albite” crystals in moonstones. The thickness of layer of these tiny crystals determine the quality of blue shimmer. Thinner the layer, better the blue flash. This usually appears as a billowy light effect. Moonstone is orthoclase feldspars, another name is “selenite”. Romans called it Astrion.

asterism

Gem cutters spiss jagħżlu li jaqtgħu forom tal-cabochon, meta l-ġebel ikun ta 'kwalità baxxa. F'dawn il-ħaġar prezzjuż u ġebel meta d-dawl jaqa 'fuq il-wiċċ tal-cabochon u jagħmel stilla-like rays, il-fenomenu jissejjaħ asterism. Hemm 4 ray u 6 ray stars osservati b'mod normali. Dan jiġri meta l-orjentazzjoni tal-inklużjonijiet bħall-labra jew il-ħarir fil-kristall tkun fuq aktar minn assi wieħed.

chatoyancy

From the french name “Chat” mean cat. Chatoyancy refers to a phenomenon akin to opening and shutting of cat’s eye. We can observe in chrysoberyl cat’s eye gem with great clarity. Cat eye gems have a single sharp band, sometimes two or three bands, running across the domed cabochon surface. Cat’s eye gemstones in cabochon shape are cut highlight chatoyancy. The straight needles of the crystal structure of the stone are perpendicular to the phenomena. So when light falls on it, the sharp band can be seen. In the best cases, the chatoyant Chrysoberyl cats eye visually separates the surface into two halves. We can see a milk and honey effect when the stone move under light.

Iridescence

Iridescence huwa magħruf ukoll bħala goniochromism, fenomenu fejn il-wiċċ ta 'materjal juri bosta kuluri hekk kif l-angolu tal-wiri jinbidel. Jista 'jkun viżibbli faċilment fl-għonq ta' ħamiem, bżieżaq tas-sapun, ġwienaħ ta 'farfett, omm tal-perla eċċ. L-irregolarità tal-wiċċ u spazji interstizjali kbar jippermettu li d-dawl jgħaddi u jirrifletti lura minn uċuħ multipli (diffrazzjoni) effett viżwali. Flimkien ma 'interferenza, ir-riżultat huwa drammatiku. Perli naturali juri l-iridixxenza li hija differenti ħafna mill-kulur tal-ġisem tagħha. Perli ta 'Tahiti juru iridixezza kbira.

Play tal-kulur

The wonderful gem called opal displays a beautiful color. The fire opals from Lightening Ridge, Australia (showing shifting patches of luminous spectral colors against black) are famous for this phenomenon. While this play of color is a type of iridescence, almost all gemstone dealers call it wrongly “fire”. Fire is a gemological term, It’s the dispersion of the light reflect in gemstones. It’s typically visible in a diamond. It is a simple dispersion of light. In case of opals it isn’t dispersion and hence, it’s wrond to use the word “fire”.

Tibdil tal-kulur

The best example of color change is alexandrite. These gems and stones appear very different in incandescent light compared to natural day light. This is largely due to the gems chemical composition as well as strong selective absorption. The alexandrite appears green in daylight and also appears red in incandescent light. Sapphire, also tourmaline, alexandrite and other stones can aslo show a color change.

Labradorescence

Labradorċence huwa tip ta 'iridescence, iżda huwa direzzjonali ħafna minħabba l-ġemellaġġ tal-kristall. Nistgħu nsibuha f'gemstone labradorite.

żball: Kontenut huwa protett !!