Agitator

Modified cement mixer used to wash dirt away from precious opal.

Boulder Opal

Formed in cavities and cracks of ironstone, usually from Queensland , Australia .

Black Opal

Naturally occurring solid opal with a coloured face and black backing.

Blower

A large truck-mounted vacuum cleaner used to suck dirt to the surface.

Cabochon

The rounded surface of a cut stone.

Chinese writing

Type of opal pattern with criss crossed strokes of colour looking like oriental letters.

Crystal

Transparent/translucent opal.

Doublet

Opal with an attached dark coloured backing.

Drive

A horizontal underground tunnel.

Free-form

A naturally shaped opal - something other than an oval or round shape.

Gouge

Mine slowly with a pick, nowadays usually only when opal is known to be present.

Harlequin

Type of opal pattern with a checkerboard appearance, rare and expensive.

Hoist

A bucket attached to a framework in a shaft, used to carry dirt to the surface.

Jelly

A type of opal with indistinct, fuzzy colours.

Level

Usually the layer of opal bearing dirt.

Matrix

Any material with specks of opal running through it.

Muggie

A cheap solid opal, having little colour or brightness.

Mullock heap

Mound of opal dirt dumped by a miner on the surface.

Nobby

Nodule of opal almost exclusively from Lightning Ridge.

Parcel

A collection of any number of opals, either rough, rubs or cut, offered for sale.

Pinfire

Type of opal pattern where specks of different colours cover the whole stone.

Potch

Opal without any colour, also called common opal.

Puddler

Forerunner of the agitator, a mesh drum.

Ratter/ratting

Thief/thieving from someone else’s mine (a serious offence).

Ribbon

Type of opal pattern with the colour running in stripes.

Rough

Opal in its natural state; as it comes out of the ground .

Rubs

Opal pieces initially shaped with waste material/sand removed but not yet cut and polished.

Rumbler

Revolving mesh drum to sort opal from dirt, now superseded by the agitator.

Seam

Opal found in a layer rather than in nobbies.

Shaft

A vertical hole down to a mine.

Solid

A naturally occurring solid piece of opal, cut into a stone.

Sunflash

Opal showing colour only from certain angles when exposed in light.

Specking

Searching through abandoned heaps of opal dirt – also called noodling.

Tailings

Material left after opal dirt from the mine has been washed.

Tail out

Search through tailings.

Tank

Dam of water on which agitators are located.

Triplet

A stone comprising a thin layer of natural opal with an attached dark backing and a clear capping.

Windlass

Forerunner of the hoist – hand operated device for raising buckets of opal dirt to the surface by means of a cable around a drum with handles.

Yowah Nut

Small ironstone boulder, containing opal either as a solid kernel or in concentric layers.