ÿþ<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>Chromascope | Kleur in diamant</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <link href="style.css" rel="stylesheet" type="text/css"> <script language="JavaScript" type="text/JavaScript"> <!-- function MM_swapImgRestore() { //v3.0 var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc; } function MM_preloadImages() { //v3.0 var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array(); var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++) if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}} } function MM_findObj(n, d) { //v4.01 var p,i,x; if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) { d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);} if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n]; for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document); if(!x && d.getElementById) x=d.getElementById(n); return x; } function MM_swapImage() { //v3.0 var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3) if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];} } //--> </script> </head> <body style="margin:0px" onLoad="MM_preloadImages('images/nav_contact_sel.gif','images/nav_product_sel.gif','images/nav_home_sel.gif','images/nav_handleiding_sel.gif')"> <table width="100%" height="100%" border="0" cellspacing="0" cellpadding="0"> <tr> <td class="leftbordertop"> <table width="100%" height="100%" cellpadding="0" cellspacing="0" border="0"> <tr><td class="leftbordertopempty">&nbsp;</td></tr> <tr> <td height="67px">&nbsp;</td> </tr> <tr> <td class="contactinfo"> <strong>Chromascope BVBA</strong><BR><BR> Schupstraat 21<BR> 2018 Antwerpen,Belgium<BR> Antwerp Diamond Area<BR><BR> Tel +32 3 232.69.67<BR> Mob +32 476 28.79.80<BR> Fax +32 3 227.54.92<BR><BR> info@chromascope.be<BR><BR> </td> </tr> </table> </td> <td class="content"> <table cellpadding="0" cellspacing="0" border="0"> <tr> <td class="centerborderlogo">&nbsp;<img src="images/logo_chromascope.jpg" border="0" width="358" height="43"></td> </tr> <tr> <td class="centerbordernavigation"> <table border="0"> <tr> <td class="navigation"><a href="home.htm" onMouseOut="MM_swapImgRestore()" onMouseOver="MM_swapImage('home','','images/nav_home_sel.gif',1)"><img src="images/nav_home.gif" alt="Home" name="home" width="92" height="25" border="0"></a></td> <td class="navigation"><a href="product.htm" onMouseOut="MM_swapImgRestore()" onMouseOver="MM_swapImage('product','','images/nav_product_sel.gif',1)"><img src="images/nav_product.gif" alt="Produkt informatie" name="product" width="79" height="25" border="0"></a></td> <td class="navigation"><img src="images/nav_kleurdiamant_sel.gif" border="0" width="79" height="25"></td> <td class="navigation"><a href="handleiding.htm" onMouseOut="MM_swapImgRestore()" onMouseOver="MM_swapImage('handleiding','','images/nav_handleiding_sel.gif',1)"><img src="images/nav_handleiding.gif" alt="Handleiding" name="handleiding" width="79" height="25" border="0"></a></td> <td class="navigation"><a href="contact.htm" onMouseOut="MM_swapImgRestore()" onMouseOver="MM_swapImage('contact','','images/nav_contact_sel.gif',1)"><img src="images/nav_contact.gif" alt="Contact" name="contact" width="92" height="25" border="0"></a></td> </tr> </table> </td> </tr> <tr> <td class="content"> <table cellspacing="10"> <tr> <td class="text"> Colour in diamond (also in other precious stones) is caused by absorption of light. White light consists in a mixture of rainbow colours. When a number of colours selectively disappear because of absorption in the diamond, one can notice the mixture of remaining colours coming back from the diamond.<BR><BR> Absorption of certain colour components is brought on by atomic and molecular impurities. A 'perfect' diamond crystal which contains no traces of impurities is colourless. As the amount of impurities increases, the colour changes.<BR><BR> The largest part of natural diamond belongs to <b>type Ia</b>. These stones contain nitrogen impurities, which mostly appear in groups of 3 nitrogen atoms (N3 aggregate). These impurities absorb blue light, which results in a yellow colour of the diamond. <BR><BR> The scale for the allocation of the colour judgement of a polished stone starts from absolute colourlessness indicated with the letter D. When a stone starts to show a pale yellow shade, this quotation drops to E, F, G, ... . Polished stones are compared to 'masterstones' in order to classify them into certain colour zones.<BR><BR> When the concentration of nitrogen impurities of a type Ia stone increases, the blue absorption increases and the diamond appears to be more yellow. This shows there is a direct connection between the concentration of impurities and the colour quotation within the &quot;D&quot; to &quot;K&quot; series and the &quot;Yellow Fancy Colours&quot;. For rough stones it is most of the time not possible to perform a reliable colour judgement by using polished 'masterstones'. The &quot;Chromascope Cape&quot; device offers a solution here. <BR><BR> The &quot;Chromascope Cape&quot; device measures the concentration of nitrogen impurities and correlates this with a judgement within the &quot;D&quot; to &quot;K&quot; series and the &quot;Yellow Fancy Colours&quot;, in other words, a colour letter is allocated to the rough stone. Since the larger part of natural diamonds belongs to type Ia, the colour of most stones can be determined.<BR><BR><BR><BR> When using the &quot;Chromascope Cape&quot;, the following restrictions need to be taken into account : <UL> <LI>For a small part of diamonds, the yellowness of the stone is determined by other impurities than nitrogen. These can not be measured by the device.</LI> <LI>The brown tint in a type II rough diamond will not be measured.</LI> <LI>Strong fluorescent stones can cause unreliable measurements.</LI> <LI>Often the colour inside a rough stone is not everywhere the same. The device however measures the average colour. It is recommended to measure the rough stone in different areas to get an idea of the colour variation present in the stone. This colour variation is caused by the fact that the concentration of nitrogen impurities is not the same in every part of the diamond.</LI> <LI>The &quot;Chromascope Cape&quot; device determines the colour from &quot;D&quot; until &quot;K&quot;. When a diamond has a lower colour than &quot;K&quot; (from &quot;L&quot; to &quot;Z&quot;), only the measured value will be given, no colour letter will be granted. When a stone becomes &quot;Yellow Fancy Colour&quot;, the device makes a distinguish between &quot;Fancy Light Yellow&quot;, &quot;Fancy Yellow&quot;, &quot;Fancy Intense Yellow&quot; and &quot;Fancy Vivid Yellow&quot;.</LI> </UL> </td> </tr> </table> </td> </tr> </table> </td> <td class="rightbordercenterempty" width="100%" height="100%"> <table width="100%" height="100%" cellpadding="0" cellspacing="0" border="0"> <tr><td class="rightbordertopempty">&nbsp;</td></tr> <tr><td class="content"></td></tr> </table> </td> <td class="diamondimage"><img src="images/diamonds.jpg" width="221" height="463"></td> </tr> <tr> <td class="leftborderbottom"><img src="images/screen.jpg" width="127" height="81"></td> <td class="centerborderslogan"><img src="images/slogan.jpg" width="520" height="81"></td> <td class="rightborderbottomempty">&nbsp;</td> </tr> </table> </body> </html>