W016 / Idaho

Spencer opal

Locality-linked opal; rough and assembled products must be distinguished

Inspect whether the object is natural rough, a thin opal layer, or an assembled doublet/triplet. Those are different comparison and pricing categories.

← Western Lapidary Materials
Verified reference photograph pending

What it is

Locality-linked opal; rough and assembled products must be distinguished

What to look for

Inspect whether the object is natural rough, a thin opal layer, or an assembled doublet/triplet. Those are different comparison and pricing categories.

At the cutting bench

Inspect the actual piece for fractures, voids and cutting orientation. Deposit-specific yield and polish data are UNKNOWN.

Under the loupe

A mounted or backed gem can conceal construction; do not use its appearance as evidence for an unidentified rough specimen.

Source & collecting access

The mine business has a current website. Public digging, current production and collecting permissions were not established from the reviewed page.

Status checked 2026-10-01

The market notebook

UNKNOWN — no verified completed-sales sample sufficient for a range

Market researched 2026-10-01

Open the field notes

Color comparison tags

White/Cream/Clear, Multicolor

Geology & evidence limits

USGS identified Spencer as an Idaho opal-producing locality in its 1995 account. That does not establish present mine output.

Collecting & trade history

The mine business has a current website. Public digging, current production and collecting permissions were not established from the reviewed page.

Reading old-stock material

Preserve the estate label, wrapping, purchase record and associated pieces. Old-stock status alone does not authenticate origin or imply a premium.

What we know—and what we don’t

Visual resemblance is a comparison clue, not proof of material identity, locality or documented provenance. Keep source labels and estate records separate from your visual assessment.

C&C Reference Collection

Reference photograph pending. Do not substitute an unlicensed dealer image or a similar-looking specimen of uncertain identity.

Sources & Further Reading
  1. Spencer Opal Mines

    Current business presence; mining/digging status not established

  2. USGS historical opal industry account

    1995; historical production only

Cut and polish with appropriate wet methods and silica-dust controls. Historic directions and mine names are not current permission to collect.