St. John Couture Blue Sparkle Evening Gown

Head turning blue striped backless halter neck gown with blue tiny shiny pieces that adorn the dress. Zip back. No material or care tag. Medium weight, not heavy, not lined, stretches. Slit at center back of dress. A few locations where the color is removed from the pieces, see neckline, otherwise completely flawless. Tag says size 6, I feel this fits like a 4/6. Top of neck to bottom of hem 53.5”, waist across 15”, hips 16.5”. Plenty of room at bust. For reference I am 5’9”, size 2/4.