Lanthanite-(Nd)
Chemical formula: Nd<sub>2</sub>(CO<sub>3</sub>)<sub>3</sub>·8H<sub>2</sub>O
A rare hydrated neodymium carbonate, forming small, pink or purplish-pink tabular crystals and coatings.
Properties
- Mohs hardness
- 2.5
- Luster
- Pearly
- Streak
- White
- Density
- 2.813
- Cleavage
- Perfect on {010}
- Fracture
- Uneven
- Transparency
- Transparent to translucent
- Crystal system
- Orthorhombic
Diagnostic features
## Identification Lanthanite-(Nd) is primarily identified by its characteristic pink or purplish-pink color, low hardness (approx. 2.5 on the Mohs scale), and occurrence as small, tabular crystals forming rosette-like aggregates. It reacts vigorously with hydrochloric acid, which is a key diagnostic feature for carbonates. ## Distinguishing from similar minerals It can be confused with other minerals from the lanthanite group, such as lanthanite-(La) and lanthanite-(Ce), from which differentiation is practically only possible through chemical analysis (e.g., EDS). Erythrite has a similar color but is an arsenate and occurs in different parageneses, often as acicular crystals. Cobaltoan calcite can also be pink but is significantly harder (approx. 4). ## Crystal forms Crystals are thin-tabular, flattened parallel to {010}, with a hexagonal or octagonal outline. They typically form small, radial or rosette-like aggregates, as well as earthy and powdery coatings on the surface of other minerals or rocks.
Geological environment
## Genesis Lanthanite-(Nd) is a secondary mineral formed in the oxidation zones of ore deposits or in pegmatites, as a result of weathering and alteration of primary rare-earth-bearing minerals, such as allanite, bastnäsite, or monazite. It forms under low-temperature conditions, with the involvement of carbon dioxide-rich waters. ## Mineral associations It often co-occurs with other minerals from the lanthanite group (lanthanite-(La), lanthanite-(Ce)), as well as with calcite, thenardite, gypsum, allanite, bastnäsite, monazite, cerussite, and anglesite. ## Localities The most important localities worldwide include the type locality in Bethlehem, Pennsylvania (USA), as well as the Curitiba mine in Paraná (Brazil) and the Mont-Saint-Hilaire quarry in Quebec (Canada). It also occurs in Sweden (Bastnäs), Japan (Suishoyama mine), and Hungary (Lahóca volcano).
Rarity
Rare
For collectors
## Quality criteria The most prized specimens of lanthanite-(Nd) are those with well-formed, sharp crystals forming aesthetic, rosette-like aggregates. The intensity and purity of the pink or purple color significantly increase the specimen's value. Contrast with the host rock and the absence of mechanical damage are also important, which is difficult to achieve due to the mineral's high delicacy. Specimens with visible, even under magnification, individual crystals are much more desirable than earthy coatings. ## Popular localities Specimens from the type locality in Pennsylvania (USA) and from Mont-Saint-Hilaire (Canada) are considered classic and most representative for this mineral.
Care and storage
## Cleaning Specimens should be cleaned only very carefully, using a soft brush to remove dust. Due to the high softness and delicacy of the crystals, contact with water is not recommended – the mineral may partially dissolve or be damaged. The use of ultrasonics is prohibited. ## What to avoid Avoid contact with all chemicals, especially acids, which rapidly decompose it with the release of carbon dioxide. The mineral is sensitive to high temperatures, under which it loses water and can be destroyed. It should be protected from moisture and direct sunlight, which can cause fading. ## Storage It is recommended to store specimens in closed, dry containers (e.g., "membrane boxes") or in stable cabinet conditions, away from sources of moisture and temperature fluctuations. Due to its softness, it should be isolated from harder minerals to avoid scratches.