Cyrtolite Zircon in Matrix - Saranac Property, near Bancroft, Ontario

Cyrtolite is the metamict, radiation-damaged variety of zircon, and this specimen shows it in matrix from the Saranac property near Bancroft, in the heart of Ontario’s Grenville Province. The zircon crystals, [description: colour, size, habit], sit in a [pegmatite / calcite / other] matrix measuring approximately [size] overall. Their typically dull, brownish tones contrast with the host rock.

Zircon naturally incorporates small amounts of uranium and thorium into its structure. Over geological time, the radioactive decay damages the crystal lattice, producing the metamict state: lower density, altered optical properties, and often a rough or slightly rounded appearance. Cyrtolite is a good teaching specimen for radiation damage in minerals, and the Bancroft area is a classic Canadian locality for it.

This is a low-level radioactive specimen, safe for collecting and display. Store it in a closed container, wash hands after handling, and do not grind or powder the material.

Approx. specimen size: 95mm x 45mm x 25mm

Approx. specimen weight: 100 grams

Approx specimen activity on an SE International Ranger EXP: 400 CPM