Ruby Slate, commonly known as Brazilian Slate, is a popular natural stone that is often used for various applications, including exterior applications. However, when it comes to using Ruby Slate in extremely dusty climates, there are a few factors to consider.

1. Porosity: Slate is generally considered a dense and low-porosity stone, which means it is less likely to absorb dust particles. However, some variations of Ruby Slate may have different porosity levels. It is important to check the specific characteristics of the particular type of Ruby Slate you plan to use for exterior applications.

2. Maintenance: In dusty climates, outdoor surfaces are more prone to accumulating dust and dirt. Regular maintenance practices, such as proper cleaning and sealing, can help maintain the appearance and longevity of the stone. This can include sweeping or hosing down the surface regularly to remove dust build-up.

3. Finishes: The surface finish of the Ruby Slate can also play a role in its suitability for dusty climates. Some finishes, like a honed or textured finish, may be more prone to trapping dust particles compared to a polished finish. However, surface finishes can also affect the slip-resistance and overall appearance, so it is important to choose the most suitable finish based on the specific requirements and conditions of the project.

4. Installation Techniques: Proper installation is crucial to maximize the performance and durability of any stone in exterior applications. Using suitable adhesives, proper sealing, and ensuring a secure and level installation can help minimize dust accumulation.

While Ruby Slate can be used in exterior applications in dusty climates, it is important to consider these factors and consult with a professional before making a final decision. Additionally, regularly maintaining the stone and cleaning it will help to mitigate the effects of dust accumulation and prolong its lifespan.