Recently on a whim, I installed a crystal knob on my bedroom bifold door closet. I can't get over how much nicer it is than the cheap knob that was there - what a delight for just $9 at Home Depot. So my recommendation would be to put the crystal on doors that YOU use a lot.

I am a matchy-match person and like the same colored hardware throughout, but think you would be fine to mix. I have seen the glass on main rooms and like you say closets/bathrooms with the porcelain.

Here is a link that might be useful: victorian doorknobs

I agree with graywings. Put them where you want them. Mixing is fine.

Here are the choices:

http://www.flickr.com/photos/68381028@N00/4392453647/in/photostream/

Crystal. The white one isn't as nice.
I recently put all ORB door knobs on all the bedroom, closet and bathroom doors with the excepton of all doors within my master bedroom. The main door which is in a nook has the matching ORB but all closets and ensuite have crystal. Makes my room a bit more regal.

Melanie, do you mind sharing where those are from?

" Since the crystal are a bit fancier, I thought of placing those on all main doors, but using the white porcelain on all the closet doors."

I've seen mixed knobs in older homes & think it's charming. I like your idea a lot: fancy glass on the showplace doors, utilitarian porcelain on the workaday doors.

We have the original white porcelain knobs with black iron rosettes and black iron hinges on all the interior doors of our ca.1900 factory worker's cottage. They do work very well with the modesty/simplicity of the house; crystal ones would be too fancy. We have all four-panel doors and mostly original trim which is extremely plain but very substantial. (Slob PO didn't bother taking off the hardware when he painted the doors, so they don't show up as nicely on the pic linked below, but it's the best picture I have of the kind of doors and trim we have. Yes, the walls and trim are the same color. Ugh. Some people should not be allowed to touch paint sprayers.) In nicer homes of similar vintage, it was very common to put the pricier lead-crystal knobs on the doors of public areas like parlors and dining rooms and use the less-expensive porcelain ones for bedrooms, utility areas like bathrooms and kitchens, etc., just like nicer trimwork was used in the public areas and simpler stuff in the private ones.

OTOH, the early-1930s Colonial Revival bungalow where I spent my teens (during the 1980s) had molded-glass 'crystal' knobs throughout the entire house to go with the molded-glass 'crystal' bowls on the ceiling light fixtures. IIRC the door and window casings were similar to mine but the house had two-panel doors. The house was almost completely original, and even then I dug that although I didn't understand what it was or why I liked it until my mid-thirties. I adored the untouched bathroom, although my parents hated the fact that it had no shower, just a bathtub - you had to sit in the tub and wash your hair with a hose that stuck onto the faucet, and wipe down the scored-plaster walls afterwards. I preferred to take baths and wash my hair in the enormous wall-hung sink. Even the toilet was original and worked perfectly after 50+ years!)

Here is a link that might be useful:

I'd use both, but not in the same room. Our house was built in 1950 and has all crystal doorknobs with brass rosettes. When we built the addition 3 years ago I opted to use oil rubbed bronze.

I like them both, but prefer the white if you have a farmhouse/cottage style. That being said, if they both make you happy- go ahead and use them both!!!!!
Do you mind me asking where you got them?

Thanks

Wow...great thoughts everyone...I really appreciate it!

The door knob brand is: NOSTALGIC WAREHOUSE... I bought them from a website company called : doorknobdiscountcenter.com

I will let you all know what I decide in the next day or two!