Natural stone is quite popular and is commonly used in building interiors, for its aesthetic appeal and for its performance, durability and environmentally-friendly composition. Natural stone also adds considerably to the real estate market value of houses. Different types of natural stone, including granite, can be used in interior design. The stones are thus exposed to staining and are affected differently depending on the staining agent involved. The European standard UNE-EN 16301:2014 defines a procedure for determining the sensitivity of ornamental stones to accidental staining. However, a more detailed study of the physical and chemical effects of such staining agents on stones is required. Adapting this standard, nine different stains (red wine, olive oil, instant coffee, ketchup, cola, citric acid, artificial urine, lime juice and blueberry juice) were applied to a granite commonly used in the Iberian Peninsula. The granite had a polished finish, and three cycles of staining-cleaning (with an anionic detergent) were applied. In the standard evaluation, a qualitative score is awarded on a text-based scale, by external evaluators. In this study, a more complex physical, chemical and texture evaluation of the granite surfaces was carried out to determine the sensitivity of the granite to accidental staining. Colour, roughness, hydrophobicity, gloss and texture were considered key parameters for evaluating the sensitivity of the granite to accidental staining.

The sensitivity of the granite to staining clearly depended on the characteristics of the staining agents. In terms of aesthetic properties, all stains except lime juice caused significant colour changes on the granite surface. None of the stains, except red wine, caused important changes in surface gloss. The staining agents, particularly ketchup, blueberry juice and citric acid increased the wettability of the granite surface, thus further enhancing the absorption of aqueous solutions. Olive oil residues were not completely removed from stone surfaces after the cleaning process and therefore caused an increase in the static contact angle, although the stained granite surfaces remained hydrophilic. Citric acid solution caused a chemical interaction with quartz grains, highlighted by the formation of etch pits.

天然石材因其美观，性能，耐用性和环保成分而广受欢迎，并常用于建筑室内。天然石材还大大增加了房屋的房地产市场价值。室内设计中可以使用不同类型的天然石材，包括花岗岩。因此，宝石会受到染色，并根据所涉及的染色剂而受到不同的影响。欧洲标准UNE-EN 16301：2014定义了确定装饰性石材对意外染色敏感性的程序。但是，需要对此类染色剂对结石的物理和化学作用进行更详细的研究。根据该标准，可以使用九种不同的污渍（红酒，橄榄油，速溶咖啡，番茄酱，可乐，柠檬酸，人造尿液，石灰汁和蓝莓汁）涂在伊比利亚半岛常用的花岗岩上。花岗岩具有抛光效果，并进行了三个周期的污渍清洁（使用阴离子型清洁剂）。在标准评估中，由外部人员以文本为基础对定性得分进行评分。评估者。在这项研究中，对花岗岩表面进行了更复杂的物理，化学和织构评估，以确定花岗岩对意外染色的敏感性。颜色，粗糙度，疏水性，光泽和质地被认为是评估花岗岩对意外污染敏感性的关键参数。

花岗岩对染色的敏感性显然取决于染色剂的特性。就美学特性而言，除柠檬汁以外的所有污渍均会导致花岗岩表面发生明显的颜色变化。除红酒外，所有污渍均未引起表面光泽的重大变化。染色剂，特别是番茄酱，蓝莓汁和柠檬酸，增加了花岗岩表面的润湿性，从而进一步增强了水溶液的吸收性。清洁过程后，橄榄油残留物并未从石材表面上完全清除掉，因此，尽管沾污的花岗岩表面仍保持亲水性，但导致静态接触角增加。柠檬酸溶液引起了与石英晶粒的化学相互作用，其突出之处在于蚀刻坑的形成。