Finding a white diamond necklace for your mother can be a special and meaningful gift. Here are some options and places to consider:

1. Local Jewelry Stores: Visit local jewelry stores in your area. They often have a variety of diamond necklaces to choose from, and you can work with the staff to find the perfect piece.
2. Online Retailers: Many reputable online retailers offer a wide selection of White Necklace. Websites like Blue Nile, James Allen, and Brilliant Earth are known for their high-quality diamond jewelry. Make sure to read reviews and check their return policies.
3. Department Stores: Stores like Macy's, Nordstrom, or Neiman Marcus often carry fine jewelry, including diamond necklaces. Check their websites or visit in person to see the options available.
4. Custom Jewelers: If you want to create a unique and personalized piece, consider working with a custom jeweler. They can help you design a necklace to your specifications.
5. Auction Houses: Occasionally, you can find exquisite estate jewelry or unique pieces at auction houses. This can be a more unique option, but it's important to research and understand the value of the item you're bidding on.
6. Local Artisan or Craft Fairs: Sometimes, local artisans create beautiful handcrafted jewelry, including White Diamond Necklace. These pieces can be unique and have a personal touch.
7. Antique Shops: If your mother appreciates vintage or antique jewelry, explore antique shops in your area. You might find a one-of-a-kind diamond necklace with a rich history.
8. Family Heirlooms: Consider asking family members if there are any heirloom pieces that have been passed down through the generations. It can be incredibly sentimental to give your mother a piece with a family history.
9. Online Marketplaces: Websites like Etsy often have a variety of jewelry makers offering unique diamond necklaces. Make sure to check the reviews and ratings of sellers.

When searching for a diamond necklace, it's important to consider the quality of the diamond (cut, color, clarity, and carat weight) and the type of metal for the necklace (white gold, platinum, silver, etc.). Additionally, consider your budget and the style that your mother would prefer, whether it's a simple solitaire pendant, a more intricate design, or a custom piece. Always ensure that you are dealing with a reputable seller, and if possible, get a certificate of authenticity for the diamond.