Guide to Crystal Lustre
Minerals exhibit various kinds of shine (known as lustre). Being able to tell the type of lustre in your crystal/minerals can help you to identify your ROXBOX crystals!
Vitreous Lustre:
This is the most common lustre, resembling the shine of glass. Minerals with a vitreous lustre are typically transparent to translucent (see through, or allow light to pass through them). Examples include quartz and amethyst.
Metallic Lustre:
True to its name, a metallic lustre resembles metal, offering a shiny and reflective surface. Minerals like pyrite and galena exhibit this lustre and are often opaque.
Matte Lustre:
Exhibiting no shine, minerals with a matte lustre have a dull surface. An example of a mineral with a matte lustre is kaolinite.
Pearly Lustre:
Iridescent and reminiscent of pearls, this lustre is seen in minerals that have fine parallel layers, such as muscovite.
Silky Lustre:
Characteristic of fibrous materials, the silky lustre gives minerals a soft, light-reflective surface, similar to silk. Asbestos and satin spar gypsum are prime examples.
Greasy Lustre:
Some minerals may appear as if they are coated with a thin layer of oil. Soapstone, with its talc content, often displays a greasy lustre.
Waxy Lustre:
This lustre makes a mineral look like it's covered in wax, which is common in minerals such as opal.
Importance of Lustre in Mineral Identification
Understanding and identifying the type of lustre a mineral possesses is a crucial step in mineral identification. It provides insights into the mineral's internal structure and composition, which are essential for classification and usage in various applications, from jewellery making to industrial purposes.