Re:녹보석(에메랄드 emerald)

<img src="https://t1.daumcdn.net/cfile/cafe/125ECC444E95371E2B" class="txc-image" width="392" height="387" style="WIDTH: 392px; FLOAT: none; HEIGHT: 387px; CLEAR: none" actualwidth="800" border="0" hspace="1" vspace="1" id="A_125ECC444E95371E2BA6EF"/>   The <A title="Gachala Emerald" href="http://en.wikipedia.org/wiki/Gachala_Emerald">Gachala Emerald</A> is one of the largest gem emeralds in the world, at 858 carats (172 g).  This stone was found in 1967 at La Vega de San Juan mine in Gachalá, Colombia. It is housed at the <A title="National Museum of Natural History" href="http://en.wikipedia.org/wiki/National_Museum_of_Natural_History">National Museum of Natural History</A> of the <A title="Smithsonian Institution" href="http://en.wikipedia.org/wiki/Smithsonian_Institution">Smithsonian Institution</A> in Washington, D.C.   <img src="https://t1.daumcdn.net/cfile/cafe/135FD64A4E9535E822" class="txc-image" width="384" height="480" style="WIDTH: 384px; FLOAT: none; HEIGHT: 480px; CLEAR: none" actualwidth="450" border="0" hspace="1" vspace="1" id="A_135FD64A4E9535E822BDE9"/>   Spanish emerald and gold pendant exhibited at <A title="Victoria and Albert Museum" href="http://en.wikipedia.org/wiki/Victoria_and_Albert_Museum">Victoria and Albert Museum</A>.   Emerald is a variety of the <A title=Mineral href="http://en.wikipedia.org/wiki/Mineral">mineral</A> <A title=Beryl href="http://en.wikipedia.org/wiki/Beryl">beryl</A> (Be3Al2(SiO3)6) colored <A title=Green href="http://en.wikipedia.org/wiki/Green">green</A> by trace amounts of <A title=Chromium href="http://en.wikipedia.org/wiki/Chromium">chromium</A> and sometimes <A title=Vanadium href="http://en.wikipedia.org/wiki/Vanadium">vanadium</A>.<A href="http://en.wikipedia.org/wiki/Emerald#cite_note-Hurlbut-1">[2]</A> Beryl has a <A class=mw-redirect title="Hardness (materials science)" href="http://en.wikipedia.org/wiki/Hardness_(materials_science)">hardness</A> of 7.5–8 on the 10 point <A title="Mohs scale of mineral hardness" href="http://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness">Mohs scale of mineral hardness</A>.<A href="http://en.wikipedia.org/wiki/Emerald#cite_note-Hurlbut-1">[2]</A>  Most emeralds are highly <A title="Inclusion (mineral)" href="http://en.wikipedia.org/wiki/Inclusion_(mineral)">included</A>, so their toughness (resistance to breakage) is classified as generally poor.     <img src="https://t1.daumcdn.net/cfile/cafe/157C89414E9537B605" class="txc-image" width="372" height="444" style="WIDTH: 372px; FLOAT: none; HEIGHT: 444px; CLEAR: none" actualwidth="596" border="0" hspace="1" vspace="1" id="A_157C89414E9537B605E322"/>   The <A title="Hooker Emerald Brooch" href="http://en.wikipedia.org/wiki/Hooker_Emerald_Brooch">Hooker Emerald Brooch</A>, containing a 75-carat square-cut emerald, also in the U.S. National Museum of Natural History.