An antique engagement ring from circa 1900 featuring a 1.80 carat Old European cut diamond would be a stunning and historically significant piece. Size 8.25 

Here's a detailed description:

Central Diamond

• Cut: Old European Cut, a predecessor to the modern round brilliant cut. This cut is characterized by its large facets, high crown, small table, and open culet, which all contribute to a unique sparkle that differs from modern diamonds.
• Carat Weight: 1.80 carats, a substantial size for an engagement ring of that era, signifying its importance and value. This diamond has been graded by the Gemological Institute of America as being J in color and VS2 in clarity.

Setting and Metal

• Metal: Platinum, a popular choice in the early 20th century for its durability and ability to hold intricate details. Platinum's white sheen also enhances the diamond's brilliance.
• Mounting: Filigree, a delicate and intricate metalwork that involves twisting and curling metal threads into ornate designs. This technique showcases the craftsmanship of the period and adds a romantic and vintage charm to the ring.

Accent Stones

• Sapphires: Small, deep blue sapphires are often used as accent stones. Their rich color complements the diamond and adds a pop of color, enhancing the overall design. These could be set alongside the central diamond or integrated into the filigree pattern.
• Diamonds: Additional small diamonds are typically used to add extra sparkle and highlight the central diamond. These are usually set in the band or around the main diamond, creating a halo effect or adorning the shoulders of the ring.

Design Details

• Circa 1900: This period was part of the Edwardian era, known for its elegance and sophistication. Jewelry from this time often features intricate designs, light and airy filigree work, and a focus on creating pieces that were both beautiful and wearable.
• Overall Aesthetic: The ring would have a delicate, lacy appearance thanks to the filigree work, with a harmonious blend of diamonds and sapphires creating a regal and timeless look. The combination of platinum with the sparkle of the diamonds and the rich blue of the sapphires would make this ring a standout piece.

Historical and Artistic Significance

• Edwardian Era Influence: The ring's design reflects the Edwardian era's love for detailed craftsmanship and elegance. This period was known for its advancements in jewelry making, particularly with platinum, which allowed for more intricate designs than previously possible with gold.
• Artistry: The use of Old European cut diamonds and filigree work showcases the high level of artistry and skill in jewelry making during this time. Each ring would be unique, often handcrafted, making it a one-of-a-kind piece.

In summary, this antique engagement ring would be a beautiful representation of early 20th-century jewelry, combining a substantial Old European cut diamond with the delicate beauty of platinum filigree work, accented by the striking contrast of sapphires and small diamonds.