Yamhamelachite
Chemical formula: KCr³⁺P₂O₇
Yamhamelachite is a rare potassium chromium pyrophosphate, forming transparent, green crystals with a vitreous luster.
Properties
- Mohs hardness
- 4-0
- Luster
- Vitreous
- Density
- 3.035
- Fracture
- Conchoidal
- Transparency
- Transparent
- Crystal system
- Monoclinic
Diagnostic features
## Identification Amateur identification of yamhamelachite is practically impossible due to its microscopic size. It requires advanced analytical techniques such as Raman spectroscopy or EDS analysis. In a collection, it is recognized based on the label and confirmed locality. Its characteristic green color and occurrence in the specific environment of the Hatrurim Formation are distinctive. ## Distinguishing from Similar Minerals It can be confused with other green secondary minerals found in the Hatrurim Formation, such as some phosphates or vanadates. Definitive differentiation is only possible through chemical and crystallographic analysis. ## Crystal Forms It forms very small, tabular or bladed crystals, usually grouped into small aggregates. Crystals rarely exceed 0.2 mm in length.
Geological environment
## Genesis Yamhamelachite is a pyrometamorphic mineral. It forms as a result of reactions occurring at very high temperatures in sedimentary rocks (marls, limestones) of the Hatrurim Formation. Its crystallization is associated with volcanic activity or prolonged, natural combustion of underground bitumen deposits, which transformed the surrounding rocks. ## Mineral Associations This mineral co-occurs with other rare minerals typical of the Hatrurim Formation, such as larnite, brownmillerite, spurrite, as well as hematite, maghemite, apatite, and calcite. ## Localities The only confirmed locality of yamhamelachite in the world is its type locality: Wadi Zohar in the Hatrurim Basin, near the road from Arad to the Dead Sea in Israel.
Rarity
Extremely rare
For collectors
## Quality Criteria As a micromineral, yamhamelachite is primarily evaluated based on the quality and size of its crystals, even though they are very small. The most desirable specimens are those with well-formed, sharp crystals of intense green color, forming rich clusters on a small rock matrix. Contrast with surrounding minerals also enhances the specimen's attractiveness. ## Popular Localities The only source of specimens is the type locality in Israel. Material from this location is extremely difficult to obtain and enters the collector's market in very limited quantities, mainly through specialized dealers or exchange among collectors.
Care and storage
## Cleaning Specimens of this mineral, due to their microscopic size and delicacy, usually do not require cleaning. If absolutely necessary, compressed air (from a safe distance) can be used to remove loose dust particles. Avoid contact with water and any chemicals. ## What to Avoid Avoid contact with water, acids, detergents, and ultrasonics. The mineral is soft (hardness 4), so it is susceptible to scratching. Protect it from high temperatures and sudden temperature changes. ## Storage Yamhamelachite specimens should be stored exclusively in specialized micromount boxes to protect them from mechanical damage, dust, and moisture. Display should be in stable conditions, away from direct sunlight.