Many fonts in iOs (and many other platforms) are shipped with one common family name but having different styles that look totally different.
For example Helvetica Neue on iOs has these styles:

"Helvetica Neue" => 
("Regular", "Bold", "Bold Italic", "Italic", "Medium", "Medium Italic",
 "Condensed Black", "Condensed Bold", "Light", "Light Italic",
 "Thin", "Thin Italic", "UltraLight", "UltraLight Italic")

But Qt Quick doesn't have a way to chose these styles (rather sub-families?)

I have tried ',' separating both but no luck

Text{
   font{
      family: "Helvetica Neue, Condensed Black"
      pixelSize: 18
   }
   text: "Not rendered as expected"
}

Update/Analysis:

On Further debugging through font matching in latest Qt code (stable branch), the issue is actually 2-fold:

• No way to specify styleName
• Bug in bestFoundry() in qfontdatabase.cpp which doesn't take care of styleName. Basically bestStyle() is being called with empty styleName which makes it to choose the first style always