ionic 2 back button or any icon is not showing. on

I am facing this icon problem in many screen. for example. i have one screen , where i have added some icon at left side of nav bar. but its not at all showing the icon. only small back box alone is showing .here is my code:

 <ion-buttons>
    <button ion-button >
        <ion-icon name="close"></ion-icon>
      </button>
       </ion-buttons

I use this also :

 <ion-buttons>
        <button ion-button >
<ion-icon ios="ios-close" md="md-close"></ion-icon>
 </button>
           </ion-buttons

but no use.still black small box icon is showing.

okay now, i tried with push nav.but there alos its not showing the back button.here is my code :

my home.html :

  <button class="button button-outline footerbtnone" (click)="login()">LOG IN</button>

my home.js

 constructor(public navCtrl: NavController) {
  }
login() {
    this.navCtrl.push(LoginPage);

  }

But when i move to LoginPage i can't see the back button icon. still i am seeing that small black box icon.here that image :

please help me out.what i am missing.

Thanks

The squares probably signal that the font is either not getting loaded properly or the browser is trying to use an alternate font face. An easy way to verify that the ionicons font is being loaded at all is to check your sources in Chrome Dev Tools. Mine looks like this: http://localhost:8100/assets/fonts/ionicons.woff2?v=3.0.0-alpha.3

If you don't see that file (or something similar) getting loaded then there's no font to render.

The ionicon font should get loaded automagically if it's referenced in your package.json file and exists in the node_modules folder. After verifying this, if the font is not getting loaded, make sure you don't have any other CSS imports/variables that are overriding the ionicons font import. e.g something like this:

 * {font-family: 'Lato' !important;}

The above will result in the ionicons font never being loaded because Lato is specified to be used for all glyphs, overriding the earlier @ionicons import.