Antique rugs are known for their unique characteristics that distinguish them from modern or contemporary rugs. When identifying an antique rug, it's essential to consider the following key features:

1. Age: An antique rug is typically defined as a rug that is at least 100 years old. Age is a crucial factor in determining its antique status.

2. Handmade: Antique rugs are almost always handwoven. The labor-intensive process of hand knotting or hand-weaving makes them more valuable and durable compared to machine-made rugs.

3. Materials: Antique rugs are traditionally made from natural materials like wool, silk, or a combination of both. The quality of these materials can significantly affect the rug's value and longevity.

4. Unique Design: Antique rugs often feature intricate and distinctive designs. These designs can include geometric patterns, floral motifs, medallions, and other decorative elements that reflect the culture and artistic traditions of their place of origin.

5. Natural Dyes: Antique rugs are commonly woven with naturally dyed fibers. Natural dyes  are derived from plants, insects, or minerals. These dyes create rich, subtle colors that age beautifully and develop a patina over time. 

6. High Knot Density: Antique rugs often have a high knot density, which means there are more knots per square inch. Higher knot density typically indicates finer craftsmanship and a more intricate design.

7. Traditional Weaving Techniques: Antique rugs are woven using traditional techniques that have been passed down through generations. The specific weaving style and knotting technique can vary depending on the region of origin.

8. Imperfections: Antique rugs may exhibit imperfections, irregularities, or asymmetries in their design or shape. These imperfections are often seen as a testament to their authenticity and handmade nature.

9. Wear and Patina: Antique rugs will show signs of wear and use, especially if they have been in use for decades or centuries. This wear can add character and depth to the rug's appearance and is considered a desirable feature by collectors.

10. Traditional Borders: Many antique rugs feature decorative borders that frame the central field. These borders often contain unique patterns or motifs that contribute to the rug's overall aesthetic.

11. Regional Characteristics: Different regions and cultures have their own distinct styles and characteristics in antique rug weaving. Understanding these regional traits can help identify the rug's place of origin.

12. Size: Antique rugs come in various sizes, from small mats to room-sized carpets. The size can provide insights into their intended use and may influence their value.

13. Signed or Dated: Some antique rugs may have the weaver's signature, date of production, or other inscriptions woven into the design. These markings can be valuable for authentication and provenance.

14. Cultural Significance: Antique rugs often hold cultural or historical significance. Understanding the cultural context of a particular rug can add depth to its appreciation.

When assessing an antique rug, it's crucial to consider these characteristics collectively to determine its authenticity and historical value. Additionally, consulting with experts or appraisers can be helpful in evaluating antique rugs accurately.