Greetings. About 25 years ago, we used a Chinese gray slate for our interior flooring—in the kitchen, bathrooms, and hallway. When we bought our 1960s era house, it had a continuous indoor outdoor flooring—brick in the hallway and on the entryway patio, and we wanted to maintain that indoor-outdoor continuity. In hindsight, it’s clear that we overinvested in a slate that was too soft for the outdoors, especially since we are a mile from the beach. Outdoors, we have used the slate for our patio, on walls capped in granite, on walls topped with redwood fencing, and at our main entrance steps. while the slate inside has weathered much better than the slate outside, it still has whitened in some places, especially in areas where it gets wet. Outdoors, however, many slate tiles have fallen off and almost all of it has whitened. We have heard that Brazilian slate is much harder than the one we used, but are nervous about going with slate again, especially considering how much we would need to replace. Trying to replace all this slate with granite, however, would be very costly. Any thoughts/suggestions on alternatives would be much appreciated! The first two photos are from the inside and the others are outside. Thanks for any guidance you can provide!