They are closely related, but not always identical in naming. Agate is banded chalcedony, while white chalcedony may be uniform and unbanded. In trade, the terms are often used interchangeably, so visible banding and product disclosure matter.

Translucency depends on internal texture, porosity, inclusion density, and thickness. Fine, compact chalcedony transmits more light, while abundant microvoids and inclusions scatter light and make the stone look milkier.

Banding forms when silica is deposited in repeated layers. Each layer reflects a change in the growth environment, such as fluid chemistry, temperature, silica concentration, flow rate, or trace mineral content.

Yes, natural white agate exists. However, chalcedony is also commonly bleached, dyed, or otherwise enhanced. Very uniform color, color in drill holes, or vague seller language can be reasons to ask for treatment disclosure.

In jewelry terminology, onyx can be banded chalcedony. In home décor and architectural stone, “onyx” often refers to banded calcite, which is softer and chemically different. Testing hardness, acid reaction, and mineral identity can separate the materials.

White agate is suitable for many jewelry styles, especially pendants, earrings, beads, and protected ring settings. Pieces with open fractures, druzy surfaces, or unknown treatments should be worn more carefully.