igneous

Porphyritic Basalt (Chinese Flower Stone / Chrysanthemum Stone basalt variety)

Porphyritic Basalt containing Plagioclase Feldspar phenocrysts

Hardness: 6-7 (Mohs scale); Color: Black or dark grey matrix with light grey, white, or greenish crystalline inclusions; Luster: Dull to sub-vitreous; Crystal structure: Porphyritic (large crystals in a fine-grained groundmass); Specific gravity: 2.8 - 3.0

Hardness: 6-7 (Mohs scale)
Luster: Dull to sub-vitreous

Identified March 27, 2026More igneous →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed from the rapid cooling of basaltic lava on the Earth's surface. The large light-colored crystals (phenocrysts) formed slowly underground before the lava erupted and the dark matrix cooled quickly. Many specimens date to the Permian period approximately 250-290 million years ago.

Uses & applications

Used primarily for decorative carving, ornamental stones, river-stone landscaping, and as collector specimens. Occasionally used in jewelry as cabochons.

Geological facts

This rock is often called 'Flower Stone' because the white feldspar crystals appear like petals against a dark background. It is chemically similar to the famous Chrysanthemum Stone, though the latter is typically a sedimentary rock with celestite or calcite crystals.

Field identification & locations

Identify in the field by the distinct 'salt and pepper' or snowflake-like contrast between the dark, dense background and the rectangular or radial light crystals. Commonly found in riverbeds in China (Hubei province) and parts of the Pacific Northwest in the USA.

Other igneous specimens

See all

Blue Apatite

Fluorapatite (Ca5(PO4)3F)

mineral

Dark Igneous Rock (Likely Basalt or Diabase)

Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.

Igneous

Magnetite

Iron(II,III) oxide (Fe3O4)

mineral

Blue Apatite

Apatite (Group), Ca5(PO4)3(F,Cl,OH)

mineral

Sodalite

Sodalite - Na8(Al6Si6O24)Cl2

mineral

Magnetite

Magnetite (Fe3O4)

mineral