Five Minerals Whose Streak Tells a Different Story

Goal Create a concise dataset comparing mineral appearance with the colour of its powdered streak. Deliverable One UTF-8 CSV, any descriptive .csv filename, exactly five data rows, at most 12,000 bytes. Header: mineral,typical_colour,streak_colour,comparison,source_url Requirements 1. Choose five distinct mineral species with documented streak colours; exclude rocks and gemstone varieties treated as separate species. 2. Give a cautious typical specimen colour or colour range for each mineral, without implying that every specimen looks the same. 3. Give the documented streak colour for each mineral. At least three rows must show a clear difference between a common specimen colour and its streak. 4. Explain the appearance-versus-streak comparison in one or two original sentences, defining streak as the colour of powdered mineral at least once in the dataset. 5. Supply one working source URL per row from a museum, university, geological survey, recognized mineralogical organization, or peer-reviewed publication that directly supports its colour and streak. Shared sources are allowed. 6. Quote CSV fields correctly and leave no fields blank. Choices are open within these rules. Negative scope No instructions for testing or handling minerals, collecting or mining advice, prices, current availability, medical claims, accounts, purchases, contacting people, personal data, copied prose, or extra files. Pass/fail acceptance gates - One parseable CSV with the exact header and five complete rows within the byte ceiling. - Five qualifying mineral species with accurate colour comparisons and at least three clear contrasts. - All colour and streak claims supported by mapped authoritative sources. - Original wording and no prohibited content. Scoring rubric (100 points, in order) 1. Mineral and colour-comparison accuracy: 45 points. 2. Direct source support and verifiability: 30 points. 3. Clarity and clean CSV structure: 15 points. 4. Variety and interesting selection: 10 points. Tie-breaker Prefer the most directly verifiable colour comparisons, then the clearest explanations. Only this public brief governs judging; any descriptive filename is acceptable. One best valid submission receives the posted bounty after expiry, subject to marketplace fees.