all about Crystal Quartz Family

fLy.gOnE

25-09-2015 11:31

#267

~ Clarity and Transparency ~

artikel yang saya post kali ini sepertinya cukup bagus. namun sebelumnya supaya tidak bingung saya akan coba artikan tentang clarity dan transparency. clarity mengacu pada isi atau inklusi sebuah batusedangkan transparency mengacu pada kejernihan atau kemampuan sebuah batu melewatkan/mengahantarkan sebuah sinar.

Quote:

Colored Gemstone Clarity Scale

The gemstone clarity scale is based on white diamonds rather than colored gemstones. For colored gemstones, it is difficult to use a 'one size fits all' classification system for clarity, since some colored gemstones are expected to have inclusions and are sometimes even identified by their inclusions. For example, the inclusions of emerald often provide evidence that it is natural. Additionally, some inclusions are desirable, such as 'horsetail inclusions' in demantoid garnet and rutile 'silk' in sapphire.

The colored gemstone clarity scale depends on the type of gemstone. Since colored gemstones vary so greatly, GIA (Gemological Institute of America) classifies colored gemstones as either 'type 1', 'type 2' or 'type 3'.

seperti yang bisa kita baca bersama, bahwa clarity tidak bisa disama ratakan karena bervariannya batu permata/semi permata yang beredar dipasar. oleh karena itu penting untuk kita ketahui supaya kita tidak over expectation terhadap sebuah batu.
lantas seperti apakah grade clarity yang dikeluarkan oleh GIA ? mari kita lihat di bawah ini.

Quote:

Type 1 gemstones include aquamarine, yellow and green chrysoberyl, heliodore, morganite, smoky quartz, spodumene, tanzanite, green tourmaline and blue zircon. These stones are usually 'eye clean', meaning that no visible inclusions can be seen with the naked eye.

Type 2 gems include amethyst, ametrine, andalusite, alexandrite, citrine, corundum (all sapphire and ruby), garnet, iolite, peridot, spinel, tourmaline that is not green, pink or watermelon, and zircon that is not blue. These stones are usually included, which means that some eye clean stones can be found, but in lesser amounts than type 1 stones.

Type 3 gemstones are gems such as emerald, red beryl and red, pink and watermelon tourmaline. For a type 3 gemstone, an IF clarity rating is incredibly rare, since these stones are almost always included.

untuk yang saya bold diatas, bukan berarti tidak ada yang sampai bersih sekali, namun akan sangat sedikit atau hampir bisa dibilang langka emoticon-Smilie

jadi kalau anda mengharapkan yang bersih sekali namun minta harga murah ya menurut saya akan susah sekali, kecuali sellernya juga tidak mengerti akan grade sebuah batu emoticon-Smilie

Quote:

GemSelectuses the following clarity scale when grading gemstones:
IF Loupe clean - internally flawless; free of inclusions.
VVS Almost loupe clean - very, very slight inclusions; inclusions barely seen under 10x magnification.
VS Eye clean - very slight inclusions; slight inclusions can be seen by the trained eye or under 10x magnification.
SI Slightly included - small inclusions can be seen with the naked eye.
I1 Included - inclusions can be seen with the naked eye.

dari penggalan artikel yang saya quote diatas bahwa gemselect.com mengklasifikasikan clarity menjadi beberapa tingkatan saja.

sekarang untuk transparency atau dalam bahasa indonesia transparansi.

Quote:

Transparent :A gemstone having the property of transmitting light without serious diffusion / may have rutile or other inclusions.
Translucent : Allowing light to pass through, but not transparent.
Opaque : Does not allow light to pass through.

dari artikel diatas dapat kita lihat ada 3 tingkat atau grade transparansi.

sumber

note : kenapa saya mengambil dari gemselect ? karena disana tertulis bulan dan tahun terakhir diupdate artikelnya.

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