Yep, I agree with browniesmom...A lot of yorkies are bigger
And regardless of size, many have different types of coats. Not all yorkies have that silky coat, many have cottony coats and wirey coats, etc. Silky terriers are also supposed to have a very silky coat, but not all of them end up having it. Here's an excerpt from AKC's description of the coat of a Silky Terrier:
Coat
Straight, single, glossy, silky in texture.
Color
Blue and tan. The blue may be silver blue, pigeon blue or slate blue, the tan deep and rich.
This is only part of what is stated, but you get the idea.
Anyway, my point is Yorkies and Silky Terriers come in all shapes and sizes and all kinds of coat textures and colors