Windowpane Oyster (also Capiz Shell)
Phylum: Mollusca, Class: Bivalvia, Order: Pectinida, Family: Placunidae, Genus: Placuna, Species: Placuna placenta · Placunidae (Windowpane Oysters) · Bivalve (Two-shelled); these specimens are worked fragments/discs modified for decor.
Species
Placuna placenta
Shell Type
Bivalve (Two-shelled); these specimens are worked fragments/discs modified for decor.
Family
Placunidae (Windowpane Oysters)
Size
2-3 inches in diameter; typically adults reach 5-6 inches, but these were cut into uniform rings.
Color & Pattern
Translucent pearly white to silvery gray with a natural iridescence (mother-of-pearl) and visible growth lines.
Rarity
Very Common; these are commercially farmed and harvested in massive quantities for the craft industry.
Habitat
Found in shallow, muddy or sandy bottoms in tropical estuarine environments or sheltered bays.
Geographic Range
Indo-West Pacific, primarily common around the Philippines, India, and across Southeast Asia.
Description
Flat, extremely thin, and translucent bivalve discs. While naturally saddle-shaped, these have been processed into round ring-shaped ornaments.
Key Features
High translucency, flaky calcitic structure, and a brilliant pearly sheen. Modified with drilled holes for stringing.
Collector Value
Low; primarily valued as craft material or interior decor (wind chimes, lamps) rather than as specimens.
Condition Notes
Modified/Worked condition. These are processed industrial products, not natural beach finds; rating: Commercial Grade.
Interesting Facts
Historically used as a substitute for glass in windows across the Philippines and India due to their translucency.
Ecological Role
Suspension feeders that help clarify water; they are a significant aquaculture species in Southeast Asia.
Similar Species
Placuna sella (Saddle Oyster), which is larger, thicker, and more distinctly purple-shaded and warped.
Beach Finding Tips
Look for flat, shimmering translucent flakes in muddy tropical flats during low tide, particularly in the Philippines.