NWA 18452 Eucrite-br Meteorite Slice, 33.79g, Mirror Polished, UV Fluorescent & Phosphorescent

UV-reactive eucrite breccia with mirror polish

This mirror-polished eucrite breccia slice exhibits both UV fluorescence and phosphorescence, an unusual optical combination rarely seen in HED meteorites. The 33.79-gram specimen shows a compact basaltic texture under its reflective surface, with the polish enhancing both visual clarity and the intensity of its UV response. When exposed to ultraviolet light, the specimen fluoresces visibly and continues to glow after the light source is removed, adding a distinct display dimension beyond typical polished eucrite material.

The specimen was classified in 2024 as Eucrite-br, confirming its status as a brecciated basaltic achondrite linked to asteroid Vesta. The mirror finish reveals the fine-grained igneous structure characteristic of eucrites while creating the optical conditions necessary to observe the phosphorescent afterglow clearly. This piece delivers both scientific classification and observable photoluminescent behavior in a single specimen.

Basaltic texture and brecciated structure

The polished surface exposes a fine-grained basaltic texture formed through crystallization of melted silicate material on a differentiated parent body. Eucrite breccias form when impact events fracture and re-consolidate igneous eucrite crust, creating a composite structure of angular clasts within a finer matrix. This specimen shows that consolidated character across its polished face, with boundaries between clasts visible under magnification and a cohesive texture that reflects its thermal and impact history.

The mirror polish eliminates surface roughness and allows light to penetrate the mineral structure efficiently, which contributes to the intensity of the UV response. Unlike rough or natural surfaces that scatter light, the polished finish provides uniform optical access to the fluorescent mineral phases distributed throughout the specimen. The result is a clean, high-contrast display under both visible and UV illumination.

Scientific context

Eucrites are basaltic achondrites that crystallized from molten lava flows on the surface of a differentiated asteroid. The HED meteorite group, which includes eucrites, diogenites, and howardites, is linked to asteroid 4 Vesta based on spectroscopic matching and confirmed by data from NASA's Dawn mission. Vesta underwent early planetary differentiation, forming a metallic core, olivine-rich mantle, and basaltic crust during the first few million years of solar system history. Eucrites represent that crustal material, delivered to Earth after impacts excavated fragments from Vesta's surface.

The UV fluorescence and phosphorescence observed in this specimen likely result from trace mineral phases or shock-induced defects in the crystal lattice. While not all eucrites exhibit these optical properties, their presence in classified HED material provides additional insight into the specimen's mineralogical composition and impact history. For an introduction to meteorite classification and parent bodies, see Learn About Meteorites.

Frequently asked questions

Is this meteorite authenticated? Yes. NWA 18452 is officially classified as Eucrite-br in the Meteoritical Bulletin. You can verify the classification here: NWA 18452. A certificate of authenticity is included with this specimen.

What causes the UV fluorescence and phosphorescence? Fluorescence occurs when UV light excites electrons in certain minerals, causing them to emit visible light. Phosphorescence is the continued glow after the UV source is removed, indicating that excited electrons release energy more slowly. In meteorites, these effects can result from trace elements, shock features, or specific mineral phases. The polished surface maximizes light penetration and enhances the visible intensity of both phenomena.

What is included with this specimen? You will receive the 33.79-gram mirror-polished eucrite slice and a certificate of authenticity confirming its classification. No display stand is included unless separately noted.

What does Eucrite-br mean? Eucrite-br indicates a brecciated eucrite. The specimen consists of eucrite fragments that were broken apart by impact, then lithified into a cohesive rock. This contrasts with unbrecciated eucrites, which retain their original igneous texture without fragmentation.

Can I display this specimen under normal lighting? Yes. The mirror polish provides a reflective, visually appealing surface under standard lighting conditions. The UV fluorescence and phosphorescence are additional features that become visible only when illuminated with a UV light source.

Why collectors acquire UV-reactive eucrites

Eucrites with observable photoluminescent properties occupy a specific niche in HED collecting. Most polished eucrite slices rely solely on texture and finish for visual appeal, but specimens that fluoresce and phosphoresce under UV light add an interactive display element. Collectors who build UV-reactive meteorite collections value material that combines official classification with clear optical performance, and this specimen delivers both.

The mirror polish ensures maximum visibility of internal structure while amplifying the UV response. At 33.79 grams, the specimen offers substantial surface area for observation and display without requiring excessive storage space. It functions equally well as a classified HED reference specimen or as a centerpiece in a photoluminescent meteorite display. Browse additional classified HED material in our Eucrites and HED Meteorites collections.

Meteoritical Bulletin entry: NWA 18452 | Classification: Eucrite-br | Find, Morocco, 2024