you can make circle without drawable
<android.support.design.widget.FloatingActionButton
android:id="@+id/bottom_navigation_fab"
style="@style/fab_material"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerInParent="true"
android:layout_gravity="bottom|center"
app:borderWidth="3dp"
android:backgroundTint="@color/mountain_meadow" // inner circle color
android:layout_marginBottom="10dp"
android:tint="@color/white"
app:backgroundTint="@color/white" // border color
app:srcCompat="@drawable/bottom_nav_star" />