London Blue Topaz Vs. Swiss Blue Topaz are two popular varieties of blue topaz, known for their stunning blue hues. Here’s a detailed comparison: London Blue Topaz Has a deep, rich blue color with hints of gray or green undertones, giving it a darker, more sophisticated appearance. Swiss Blue Topaz Has a bright, vibrant blue color, often compared to tropical waters or clear skies. It’s lighter than London Blue but still bold, with an intense, electric blue shade that makes it popular for statement pieces.