Guides

Amethyst has occupied a distinctive place in jewellery history because its violet colour combines visual drama with a long tradition of protective symbolism.…

A star sapphire is prized for the six-rayed asterism that appears when a polished cabochon catches light from a single source. In the Australian market, the…

Low light punishes vague cutting more readily than bright daylight. A stone may look lively in a jeweller’s spotlit case, then lose its fire beneath office…

Labradorite is admired for its sudden flashes of blue, green, gold and violet. A grey or charcoal stone may appear quiet in ordinary light, then reveal a vivid…

December’s birthstone trio—tanzanite, turquoise and zircon—combines distinct expressions of colour and character. Tanzanite is usually blue with violet…

Opal is a delicate, hydrated form of silica, and its famous play-of-colour depends partly on water held within the stone. As that moisture evaporates, the…

The art of micropave on a diamond band comes down to scale. Rows of minute diamonds are seated into recesses cut into the metal, creating a surface of…

Tourmaline is famous for an exceptional range of hues, from ruby-red and pink to blue, green, yellow, brown, black and even colourless. Much of that variety…

The science of refractive index in gem grading begins with light changing speed and direction when it enters a gemstone. Its refractive index, usually written…

A pearl strand can fail in several ways: elastic may snap, silk may stretch or fray, a knot may loosen, or the clasp may open. The appropriate repair depends…