{"product_id":"chelsea-colour-filter","title":"Chelsea Colour Filter","description":"\u003cdiv class=\"product__description rte quick-add-hidden\"\u003e\n\u003cp\u003e\u003cspan\u003eThe Chelsea colour filter (CCF) is a tool used in gemmology. It transmits only deep red  and yellow-green light. The result is, some similarly coloured gems can look very different through the filter. For example syntehtic blue spinel coloured by cobalt looks pink to bright red, whereas natural blue sapphire will usually look dull or dark.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThis assists users to quickly spot rogue stones in parcels or multi stone set jewellery, and also as another piece of data for full gem testing. It can help differentiate many natural, synthetic, artificial or treated gemstones with experience and training.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIf you want to learn how to use a CCF, why not do one of our courses 😉?!\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Sachi","offers":[{"title":"Default Title","offer_id":57962558783862,"sku":"GIN001","price":25.0,"currency_code":"GBP","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0412\/6795\/3821\/files\/20260527_125612.jpg?v=1779891195","url":"https:\/\/gemmologyrocks.com\/products\/chelsea-colour-filter","provider":"Gemmology Rocks","version":"1.0","type":"link"}