Optimization for android

Hello!

I have a couple of optimization questions. I want to make out an example of my app. My app have a static class of inventory. In this class awake method is initializing the data.

// field in my inventory class

Code (csharp):

1.  
2. public static Item item;
3.  

// init in awake method in inventory class

Code (csharp):

1.  
2. item = new Item("Name", "MaterialName");
3.  

// item class

Code (csharp):

1.  
2. [System.Serializable]
3. public class Item
4. {
5.        public string name;
6.        public Material materialName;
7.  
8.        public Item(string name, string materialName)
9.        {
10.               this.name= name;
11.               this.materialName= Resources.Load("Materials/Items/" + materialName) as Material;
12.  
13.               Inventory.instance.AddToItemRegistery(this);
14.        }
15. }
16.  

The copy of every item always is located in memory and i think it's can cause crashes on some devices. I have >60 items. Each item contains material and each material contain aldebo texture, metall map and normal map. Some people says that game crash and i think this inventory system may be a problem. I think that i need to hold only material name in the item class. Only when i need to use material i should make GetMaterial function that will load material by name in run time. Also i can make only one material and change textures in run time. What is way will be best for performance?

Also I have a lot of textures. Different profiles. Albedo, metal and normal maps. I can not keep them in the atlas maps, so I think that they need to be compressed. But I do not know how to do it better. I want to hear your opinion so.