Metamorphic Rocks: What to Record

Identification

Rock name Text Rocks

Petrographic name, e.g. granite, basalt, sandstone, gneiss.

Texture Text Rocks

Grain size and fabric, e.g. coarse-grained, porphyritic, vesicular, foliated, cross-bedded.

Mineral content Text Rocks

Main minerals and their approximate shares.

Colour Text Rocks

Colour or colours as seen in daylight, main colour first.

Geology

Geological unit and age.

Formation Text Rocks

Rock unit (lithostratigraphy), e.g. Hell Creek Formation, Solnhofen Limestone, Posidonia Shale.

Geologic period Choice Rocks

Geologic period after the International Chronostratigraphic Chart (ICS 2024/12); Ma = million years ago.

13 choices

• Precambrian (before 538.8 Ma)
• Cambrian (538.8 to 486.9 Ma)
• Ordovician (486.9 to 443.1 Ma)
• Silurian (443.1 to 419.6 Ma)
• Devonian (419.6 to 358.9 Ma)
• Carboniferous (358.9 to 298.9 Ma)
• Permian (298.9 to 251.9 Ma)
• Triassic (251.9 to 201.4 Ma)
• Jurassic (201.4 to 143.1 Ma)
• Cretaceous (143.1 to 66.0 Ma)
• Paleogene (66.0 to 23.0 Ma)
• Neogene (23.0 to 2.58 Ma)
• Quaternary (2.58 Ma to today)

Epoch / stage Text Rocks

Finer age, e.g. Late Cretaceous, Maastrichtian; Middle Devonian, Eifelian.

Age (Ma) Number Rocks

Age in million years, when known from the literature or a dating.

Specimen

Preparation Choice, or your own Rocks

How the sample is prepared.

• Hand specimen (rough)
• Cut slab
• Polished
• Thin section
• Sphere / carving

Height (cm) Number Rocks

Height, measured upright as the object is meant to stand or hang.

Width (cm) Number Rocks

Width, measured from the front.

Depth (cm) Number Rocks

Depth, measured from front to back.

Weight (g) Number Rocks

Weight of the object (without stand, frame or holder unless noted).

Origin

Locality Text Rocks

Exact find site, as specific as possible, e.g. quarry, mine and level, beach, outcrop.

Region Text Rocks

State, province, county or district of the locality.

Country Text Rocks

Country of origin or issue, by its usual English name (historic states as named at the time, e.g. Kingdom of Bavaria).

Coordinates Place Rocks

Geographic position of the locality (keep private for sensitive sites).

Collected by Text Rocks

Person who collected or excavated the specimen.

Collection date Date Rocks

Date the specimen was collected in the field.

Acquisition

How and when the object came into the collection.

Acquisition date Date Rocks

Date the object came into the collection.

Acquisition method Choice, or your own Rocks

How the object came into the collection.

• Purchase
• Auction
• Gift
• Inheritance
• Exchange / trade
• Self-collected / found
• Commission

Acquired from Text Rocks

Seller, auction house (with sale and lot number), donor or place where it was found.

Purchase price Amount Rocks

Price paid including fees and premiums.

Provenance Text Rocks

Earlier owners and the object's history, oldest first, with sources (labels, invoices, sale catalogues).

Value

Estimated and insured value.

Estimated value Amount Rocks

Current market value as estimated.

Valuation date Date Rocks

Date of the current value estimate.

Valuation basis Choice Rocks

What the estimated value is based on.

• Own estimate
• Recent sales / auction results
• Dealer offer
• Catalogue value
• Professional appraisal
• Insurance valuation

Insured value Amount Rocks

Sum the object is insured for.

Collection record

Your own inventory data.

Inventory number Text Rocks

Your own number or label for the object, e.g. C-0042, as written on its label or album page.

Storage location Text Rocks

Where the object is kept, e.g. room, cabinet, drawer, album and page, box.